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SCIENCE  IN  SHORT  CHAPTERS 


BY 


W.  MATTIEU  WILLIAMS,  F.R.A.S.,  F.C.S., 

AUTHOR  OP  "THE  FUEL  OF  THE  SUN,"   "THROVOH  NORWAY  WITH  A  KNAPSACK," 
"A  SIMPLE  TBEATISB  ON  HEAT,"  ETC. 


NEW  YORK: 

FUNK  &  WAGNALLS,  PUBLISHERS, 
10  AND  12  DEY  STREET. 


Ml 


•AY  21 
•  *•  ^^»  •  • 


PREFACE. 

THIS  book  supplies  a  growing  want  of  these  busy  times,  when 
so  many  of  us  are  prevented  by  the  struggles  of  business  from 
sitting  down  to  the  consecutive  systematic  study  of  a  formal 
treatise. 

I  have  kept  this  demand  steadily  in  view  throughout,  by  select- 
ing subjects  which  are  likely  to  be  interesting  to  all  readers  who 
are  sufficiently  intelligent  to  prefer  sober  fact  to  sersational  fiction, 
but  who,  at  the  same  time,  do  not  profess  to  be  scientific  specialists. 

In  the  writing  of  these  papers  my  highest  literary  ambition  has 
always  been  to  combine  clearness  and  simplicity  with  some  attempt 

"•»•••         !     •  £ 

at  philosophy. 

W.  M.  W. 

WILLESDEN,  September,  1882. 


267733 


PUBLISHERS'  NOTE  TO  THE  AMERICAN  EDITION. 

THIS  edition,  prepared  for  American  readers,  contains  the  com- 
plete text  of  the  English  edition  ;  nothing  has  been  omitted  ;  but 
the  order  of  the  articles  has  been  changed  so  as  to  make  a  more 
interesting  arrangement  of  the  subjects. 

NEW  YORK,  January  15,  1883. 


CONTENTS. 


PAG* 

ANOTHER  WORLD  DOWN  HERE,             ....  7 

CONCERT-BOOH  ACOUSTICS,         .....  15 

ORIGIN  OF  SOAP,            ......  21 

OILING  THE  WAVES,       ......  25 

THE  ACTION  OP  FROST  IN  WATER-PIPES  AND  ON  BUILDING 

MATERIALS,              ......  30 

FIRE-CLAY  AND  ANTHRACITE,     .....  37 

COUNT  RUMFORD'S  COOKING-STOVES,     ....  45 

THE  "  CONSUMPTION  OF  SMOKE,"          .            .                        .  51 

THE  AIR  OF  STOVE-HEATED  ROOMS,     ....  55 

VENTILATION  BY  OPEN  FIREPLACES,      .            .            .    •»  60 

DOMESTIC  VENTILATION,             .....  64 

THE  FUEL  OF  THE  SUN,            .            •            .            .            .  72 

DR.  SIEMENS'S  THEORY  OF  THE  SUN,  ....  99 

THE  ORIGIN  OF  LUNAR  VOLCANOES,     ....  102 

NOTE  ON  THE  DIRECT  EFFECT  OF  SUN-SPOTS  ON  TERRES- 
TRIAL CLIMATES,     .            .            .                         .            .  108 

THE  PHILOSOPHY  OF  THE  RADIOMETER  AND  ITS  COSMICAL 

REVELATIONS,           .                     •    .            .            .            .  110 

ON  THE  SOCIAL  BENEFITS  OF  PARAFFINE,        .            .            .  116 

THE  SOLIDITY  OF  THE  EARTH,              ....  122 

A  CONTRIBUTION  TO  THE  HISTORY  OF  ELECTRIC  LIGHTING,  125 

THE  FORMATION  OF  COAL,         .            .            .            .            .  133 


Tl  CONTENTS. 

PAGE 

THE  SOLAE  ECLIPSE  or  1871,               .            .            .           ".  140 

METEORIC  ASTEONOMY,    .             .            .                          .             .  150 

THE  "  GREAT  ICE  AGE"  AND  THE  ORIGIN  OF  THE  "TiLL, "  .  157 

THE  BAROMETER  AND  THE  WEATHER,               .            .            .  181 

THE  CHEMISTRY  OF  BOG  RECLAMATION,            .            .            .  199 

AERIAL  EXPLORATION  OF  THE  ARCTIC  REGIONS            .            .  208 

THE  LIMITS  OF  OUR  COAL  SUPPLY,      *-           .            »         •  .  220 

"THE  ENGLISHMAN'S  FIRESIDE,"          .        _   .-          .            .  235 

"BAILY'S  BEADS,"          .            .            .            .            .            .  240 

THE  COLORING  OF  GREEN  TEA,            ....  242 

"IRON  FILINGS"  IN  TEA,         .....  244 

SCIENCE  AND  SPIRITUALISM,      .            .            .            .            .  247 

MATHEMATICAL  FICTIONS,           ....           '.  256 

WORLD-SMASHING,          .             .             .             .             .             .  359 

THE  DYING  TREES  IN  KENSINGTON  GARDENS,  .  .  262 
THE  OLEAGINOUS  PRODUCTS  OF  THAMES  MUD  :  WHERE  THEY 

COME  FROM  AND  WHERE  THEY  Go,           .            .            .  2C5 

LUMINOUS  PAINT,           .             .            .            .            .            .  267 

THE  ORIGIN  AND  PROBABLE  DURATION  OF  PETROLEUM,  .  270 
ON  THE  SO-CALLED  "CRATER  NECKS "  AND  "VOLCANIC 

BOMBS"   OF  IRELAND,         .            .            .            .            .  275 

TRAVERTINE,       .......  279 

THE  CORROSION  OF  BUILDING  STONES,             .            .            .  281 

HOME  GARDENS  FOR  SMOKY  TOWNS,     ....  284 

SOLIDS,  LIQUIDS,  AND  GASES,  .  .  »  .  294 

MURCHISON  AND  BABBAGE,  .  .  .  .  •  307 


SCIENCE  IN  SHORT  CHAPTERS* 


CHAPTER  I. 

ANOTHER    WORLD    DOWN    HERE. 

WHAT  a  horrible  place  must  this  world  appear  when  re- 
garded according  to  our  ideas  from  an  insect's  point  of  view  ! 
The  air  infested  with  huge  flying  hungry  dragons,  whose 
gaping  and  snapping  mouths  are  ever  intent  upon  swallowing 
the  innocent  creatures  for  whom,  according  to  the  insect,  if  lie 
were  like  us,  a  properly  constructed  world  ought  to  be  exclu- 
sively adapted.  The  solid  earth  continually  shaken  by  the 
approaching  tread  of  hideous  giants — moving  mountains — that 
crush  our  precious  lives  at  every  footstep,  an  occasional 
draught  of  the  blood  of  these  monsters,  stolen  at  life-risk, 
affording  but  poor  compensation  for  such  fatal  persecution. 

Let  us  hope  that  the  little  victims  are  less  like  ourselves  than 
the  doings  of  ants  and  bees  might  lead  us  to  suppose  ;  that 
their  mental  anxieties  are  nut  proportionate  to  the  optical 
vigilance  indicated  by  the  four  thousand  eye-lenses  of  the 
common  house-fly,  the  seventeen  thousand  of  the  cabbage  but- 
terfly and  the  wide-awake  dragon-fly,  or  the  twenty-five  thous- 
and possessed  by  certain  species  of  still  more  vigilant  beetles. 

Each  of  these  little  eyes  has  its  own  cornea,  its  lens,  and  a 
curious  six-sided,  transparent  prism,  at  the  back  of  which  is  a 
special  retina  spreading  out  from  a  branch  of  the  main  optic 
nerve,  which,  in  the  cockchafer  and  some  other  creatures,  i? 
half  as  large  as  the  brain.  If  each  of  these  lenses  forms  a 
separate  picture  of  each  object  rather  than  a  single  mosaic 
picture,  as  some  anatomists  suppose,  what  an  awful  army  of 
cruel  giants  must  the  cockchafer  behold  when  he  is  captured 
by  a  schoolboy  ! 

*  The  order  of  the  articles  has  been  changed  in  this  edition.  See 
Publishers'  note  on  page  4. 


8  \  v  SCIENCE  127  SHOUT  CHAPTERS. 

The  insect  must  see  a  whole  world  of  wonders  of  which  we 
know  little  or  nothing.  True,  we  have  microscopes,  with 
which  we  can  see  one  thing  at  a  time  if  carefully  laid  upon  the 
stage  ;  but  what  is  the  finest  instrument  that  Ross  can  produce 
compared  to  that  with  twenty -five  thousand  object-glasses,  all 
of  them  probably  achromatic,  and  each  one  a  living  instru- 
ment, with  its  own  nerve-branch  supplying  a  separate  sensa- 
tion ?  To  creatures  thus  endowed  with  microscopic  vision,  a 
cloud  of  sandy  dust  must  appear  like  an  avalanche  of  massive 
rock-fragments,  and  everything  else  proportionally  monstrous. 

One  of  the  many  delusions  engendered  by  our  human  self- 
conceit  and  habit  of  considering  the  world  as  only  such  as  we 
know  it  from  our  human  point  of  view,  is  that  of  supposing 
human  intelligence  to  be  the  only  kind  of  intelligence  in  exist- 
ence. The  fact  is,  that  what  we  call  the  lower  animals  have 
special  intelligence  of  their  own  as  far  transcending  our  in- 
telligence as  our  peculiar  reasoning  intelligence  exceeds  theirs. 
We  are  as  incapable  of  following  the  track  of  a  friend  by  the 
smell  of  his  footsteps  as  a  dog  is  of  writing  a  metaphysical 
treatise. 

So  with  insects.  They  are  probably  acquainted  with  a  whole 
world  of  physical  facts  of  which  we  are  utterly  ignorant.  Our 
auditory  apparatus  supplies  us  with  a  knowledge  of  sounds. 
What  are  these  sounds  ?  They  are  vibrations  of  matter  which 
are  capable  of  producing  corresponding  or  sympathetic  vibra- 
tions of  the  drums  of  our  ears  or  the  bones  of  our  skull. 
When  we  carefully  examine  the  subject,  and  count  the  number 
of  vibrations  that  produce  our  world  of  sounds  of  varying 
pitch,  we  find  that  the  human  ear  can  only  respond  to  a  limited 
range  of  such  vibrations.  If  they  exceed  three  thousand  per 
second,  the  sound  becomes  too  shrill  for  average  people  to  hear 
it,  though  some  exceptional  ears  can  take  up  pulsations  or 
waves  that  succeed  each  other  more  rapidly  than  this. 

Reasoning  from  the  analogy  of  stretched  strings  and  mem- 
branes, and  of  air  vibrating  in  tubes,  etc.,  we  are  justified  in 
concluding  that  the  smaller  the  drum  or  the  tube  the  higher  will 
be  the  note  it  produces  when  agitated,  and  the  smaller  and  the 
more  rapid  the  aerial  wave  to  which  it  will  respond.  The 
drums  of  insect  ears,  and  the  tubes,  etc.,  connected  with 
them,  are  so  minute  that  their  world  of  sounds  probably  begins 
where  ours  ceases  ;  that  the  sound  which  appears  to  us  as  con- 
tinuous is  to  them  a  series  of  separated  blows,  just  as  vibrations 
of  ten  or  twelve  per  second  appear  to  us.  We  begin  to  hear 


ANOTHER  WORLD   DOWN  HERE.     t  9 

such  vibrations  as  continuous  sounds  when  they  amount  to 
about  thirty  per  second.  The  insect's  continuous  sound  prob- 
ably begins  beyond  three  thousand.  The  blue-bottle  may  thus 
enjoy  a  whole  world  of  exquisite  music  of  which  we  know 
nothing. 

There  is  another  very  suggestive  peculiarity  in  the  auditory 
apparatus  of  insects.  Its  structure  and  position  are  something 
between  those  of  an  ear  and  of  an  eye.  Careful  examination 
of  the  head  of  one  of  our  domestic  companions — the  common 
cockroach  or  black-beetle — will  reveal  two  round  white  points, 
somewhat  higher  than  the  base  of  the  long  outer  antenna, 
and  a  little  nearer  to  the  middle  line  of  the  head.  These  white 
projecting  spots  are  formed  by  the  outer  transparent  membrane 
of  a  bag  or  ball  filled  with  fluid,  which  ball  or  bag  rests  inside 
another  cavity  in  the  head.  It  resembles  our  own  eye  in  hav- 
ing this  external  transparent  tough  membrane  which  corre- 
sponds to  the  cornea  or  transparent  membrane  forming  the 
glass  of  our  eye-window  ;  which,  like  the  cornea,  is  backed 
by  the  fluid  in  an  ear-ball  corresponding  to  our  eyeball,  and 
the  back  of  this  ear-ball  appears  to  receive  the  outspreadings 
of  a  nerve,  just  as  the  back  of  our  eye  is  lined  with  that  out- 
spread of  the  optic  nerve  forming  the  retina.  There  does  not 
appear  to  be  in  this  or  other  insects  a  tightly  stretched  mem- 
brane which,  like  the  membrane  of  our  ear-drum,  is  fitted  to 
take  up  bodily  air-waves  and  vibrate  responsively  to  them. 
But  it  is  evidently  adapted  to  receive  and  concentrate  some 
kind  of  vibration,  or  motion,  or  tremor. 

What  kind  of  motion  can  this  be  ?  What  kind  of  per- 
ception does  this  curious  organ  supply  ?  To  answer  these 
questions  we  must  travel  beyond  the  strict  limits  of  scientific 
induction  and  enter  the  fairyland  of  scientific  imagination. 
We  may  wander  here  in  safety,  provided  we  always  remem- 
ber where  we  are,  and  keep  a  true  course  guided  by  the  com- 
pass-needle of  demonstrable  facts. 

I  have  said  that  the  cornea-like  membrane  of  the  insect's 
ear-bag  does  not  appear  capable  of  responding  to  bodily  air- 
waves. This  adjective  is  important,  because  there  are  vibratory 
movements  of  matter  that  are  not  bodily  but  molecular.  An 
analogy  may  help  to  render  this  distinction  intelligible.  I  may 
take  a  long  string  of  beads  and  shake  it  into  wavelike  move- 
ments, the  waves  being  formed  by  the  movements  of  the  whole 
string.  We  may  now  conceive  another  kind  of  movement  or 
vibration  by  supposing  one  bead  to  receive  a  blow  pushing  it 


10  SCIENCE   1$   SHORT   CHAFFERS. 

forward,  this  push  to  be  communicated  to  the  next,  then  to 
the  third,  and  so  on,  producing  a  minute  running  tremor 
passing  from  end  to  end.  This  kind  of  action  may  be  rendered 
visible  by  laying  a  number  of  billiard  balls  or  marbles  in  line 
and  bowling  an  outside  ball  against  the  end  one  of  the  row. 
The  impulse  will  be  rapidly  and  invisibly  transmitted  all  along 
the  line,  and  the  outer  ball  will  respond  by  starting  forward. 

Heat,  light,  and  electricity  are  mysterious  internal  move- 
ments of  what  we  call  matter  (some  say  **  ether,"  which  is  but 
a  name  for  imaginary  matter. )  These  internal  movements  are 
as  invisible  as  those  of  the  intermediate  billiard  balls  ;  but  if 
there  be  a  line  of  molecules  acting  thus,  and  the  terminal  one 
strikes  an  organ  of  sense  fitted  to  receive  its  motion,  some  sort 
of  perception  may  follow.  When  such  movements  of  certain 
frequency  and  amplitude  strike  our  organs  of  vision,  the  sensa- 
tion of  light  is  produced.  When  others  of  greater  amplitude 
and  smaller  frequency  strike  the  terminal  outspread  of  our 
common  sensory  nerves,  the  sensation  of  heat  results.  The 
difference  between  the  frequency  and  amplitude  of  the  heat 
waves  and  the  light  waves  is  but  small,  or,  strictly  speaking, 
there  is  no  actual  line  of  separation  lying  between  them  ; 
they  run  directly  into  each  other.  When  a  piece  of  metal  is 
gradually  heated,  it  is  first  "  black-hot ;"  this  is  while  the 
waves  or  molecular  tremblings  are  of  a  certain  amplitude  and 
frequency  ;  as  the  frequency  increases  and  amplitude  dimin- 
ishes (or,  to  borrow  from  musical  terms,  as  the  pitch  rises), 
the  metal  becomes  dull  red-hot ;  greater  rapidity,  cherry  red  ; 
greater  still,  bright  red  ;  then  yellow-hot  and  white-hot  :  the 
luminosity  growing  as  the  rapidity  of  molecular  vibration 
increases. 

There  is  no  such  gradation  between  the  most  rapid  undula- 
tions or  tremblings  that  produce  our  sensation  of  sound  and 
the  slowest  of  those  which  give  rise  to  our  sensations  of 
gentlest  warmth.  There  is  a  huge  gap  between  them,  wide 
enough  to  include  another  world  or  several  other  worlds  of 
motion,  all  lying  between  our  world  of  sounds  and  our  world 
of  heat  and  light,  and  there  is  no  good  reason  whatever  for 
supposing  that  matter  is  incapable  of  such  intermediate  activity, 
or  that  such  activity  may  not  give  rise  to  intermediate  sensa- 
tions, provided  there  are  organs  for  taking  up  and  sensifying 
(if  I  may  coin  a  desirable  word)  these  movements. 

As  already  stated,  the  limit  of  audible  tremors  is  three  to 
four  thousand  per  second,  but  the  smallest  number  of  tremors 


ANOTHER   WORLD    DOAVX   HERE.     f  11 

that  we  can  perceive  as  heat  is  between  three  and  four  millions 
of  millions  per  second.  The  number  of  waves  producing  red 
light  is  estimated  at  four  hundred  and  seventy-four  millions  of 
millions  per  second  ;  and  for  the  production  of  violet  light, 
six  hundred  and  ninety-nine  millions  of  millions.  These  are 
the  received  conclusions  of  our  best  mathematicians,  which  I 
repeat  on  their  authority.  Allowing,  however,  a  very  large 
margin  of  possible  error,  the  world  of  possible  sensations  lying 
between  those  produced  by  a  few  thousands  of  waves  and  any 
number  of  millions  is  of  enormous  width. 

In  such  a  world  of  intermediate  activities  the  insect  probably 
lives,  with  a  sense  of  vision  revealing  to  him  more  than  our 
microscopes  show  to  us,  and  with  his  minute  eye-like  ear-bag 
scnsifying  material  movements  that  lie  between  our  world  of 
sounds  and  our  other  far-distant  worlds  of  heat  and  light. 

There  is  yet  another  indication  of  some  sort  of  intermediate 
sensation  possessed  by  insects.  Many  of  them  are  not  only 
endowed  with  the  thousands  of  lenses  of  their  compound  eyes, 
but  have  in  addition  several  curious  organs  that  have  been 
designated  "  ocelli  "  and  "  stemrnata."  These  are  generally 
placed  at  the  top  of  the  head,  the  thousand-fold  eyes  being  at 
the  sides.  They  are  very  much  like  the  auditory  organs  above 
described — so  much  so  that  in  consulting  different  authorities 
for  special  information  on  the  subject  I  have  fallen  into  some 
confusion,  from  which  I  can  only  escape  by  supposing  that  the 
organ  which  one  anatomist  describes  as  the  ocelli  of  certain 
insects  is  regarded  as  the  auditory  apparatus  when  examined 
in  another  insect  by  another  anatomist.  All  this  indicates  a 
sort  of  continuity  of  sensation  connecting  the  sounds  of  the 
insect  world  with  the  objects  of  their  vision. 

But  these  ocular  ears  or  auditory  eyes  of  the  insect  are  not 
his  only  advantage  over  us.  He  has  another  sensory  organ  to 
which,  with  all  our  boasted  intellect,  we  can  claim  nothing  that 
is  comparable,  unless  it  be  our  olfactory  nerve.  The  possibil- 
ity of  this  I  will  presently  discuss. 

I  refer  to  the  antenna,  which  are  the  most  characteristic  of 
insect  organs,  and  wonderfully  developed  in  some,  as  many  be 
seen  by  examining  the  plumes  of  the  crested  gnat.  Every- 
body who  has  carefully  watched  the  doings  of  insects  must 
have  observed  the  curiously  investigative  movements  of  the 
antenna?,  which  are  ever  on  the  alert,  peering  and  prying  to 
right  and  left  and  upward  and  downward.  Huber,  who 
devoted  his  life  to  the  study  of  bees  and  ants,  concluded  that 


12  SCIENCE   IK   SHOUT   CHAPTERS. 

these  insects  converse  with  each  other  by  movements  of  the 
antennae,  and  he  has  given  to  the  signs  thus  produced  the  name 
of  *'  antennal  language."  They  certainly  do  communicate 
information  or  give  orders  by  some  means  ;  and  when  the 
insects  stop  for  that  purpose,  they  face  each  other  and  execute 
peculiar  wavings  of  these  organs  that  are  highly  suggestive  of 
the  movements  of  the  old  semaphore  telegraph  arms. 

The  most  generally  received  opinion  is  that  these  antennae 
are  very  delicate  organs  of  touch,  but  some  recent  experiments 
made  by  Gustav  Hansen  indicate  that  they  are  organs  of 
smelling  or  of  some  similar  power  of  distinguishing  objects  at 
a  distance.  Flies  deprived  of  their  antennae  ceased  to  display 
any  interest  in  tainted  meat  that  had  previously  proved  very 
attractive.  Other  insects  similarly  treated  appear  to  become 
indifferent  to  odors  generally.  He  shows  that  the  develop- 
ment of  the  antennae  in  different  species  corresponds  to  the 
power  of  smelling  which  they  seem  to  possess. 

I  am  sorely  tempted  to  add  another  argument  to  those 
brought  forward  by  Hansen — viz.  that  our  own  olfactory  nerves, 
and  those  of  all  our  near  mammalian  relations,  are  cuiiously 
like  a  pair  of  antennae. 

There  are  two  elements  in  a  nervous  structure,  the  gray  and 
the  white  ;  the  gray  or  ganglionic  portion  is  supposed  to  be 
the  centre  or  seat  of  nervous  power,  and  the  white  medullary 
or  fibrous  portion  merely  the  conductor  of  nervous  energy. 

The  nerves  of  the  other  senses  have  their  ganglia  seated 
internally,  and  bundles  of  tubular  white  threads  spread  out- 
ward therefrom  ;  but  not  so  with  the  olfactory  nervous  appara- 
tus. These  present  two  horn-like  projections  that  are  thrust 
forward  from  the  base  of  the  brain,  and  have  white  or  medul- 
lary stems  that  terminate  outwardly  or  anteriorly  in  ganglionic 
bulbs  resting  upon  what  I  may  call  the  roof  of  the  nose  ;  these 
bulbs  throw  out  fibres  that  are  composed,  rather  paradoxically, 
of  more  gray  matter  than  white.  In  some  quadrupeds  with 
great  power  of  smell,  the  olfactory  nerves  extend  so  far  for- 
ward as  to  protrude  beyond  the  front  of  the  hemispheres  of 
the  brain,  with  bulbous  terminations  relatively  very  much  larger 
than  those  of  man. 

They  thus  appear  like  veritable,  antennae.  In  some  of  our 
best  works  on  anatomy  of  the  brain  (Solly,  for  example)  a 
series  of  comparative  pictures  of  the  brains  of  different  animals 
is  shown,  extending  from  man  to  the  cod-fish.  As  we  proceed 
downward,  the  horn-like  projection  of  the  olfactory  nerves 


ANOTHER   WORLD   DOW^   HERE.  13 

beyond  the  "central  hemispheres  goes  on  extending  more  and 
more,  and  the  relative  magnitude  of  the  terminal  ganglia  or 
olfactory  lobes  increases  in  similar  order. 

We  have  only  to  omit  the  nasal  bones  and  nostrils,  to  con- 
tinue this  forward  extrusion  of  the  olfactory  nerves  and  their 
bulbs  and  branches,  to  coat  them  with  suitable  sheaths  provided 
with  muscles  for  mobility,  and  we  have  the  antenna  of  insects. 
I  submit  this  view  of  the  comparative  anatomy  of  these  organs 
as  my  own  speculation,  to  be  taken  for  what  it  is  worth. 

There  is  no  doubt  that  the  antennae  of  these  creatures  are 
connected  by  nerve-stalks  with  the  anterior  part  of  their 
supra-iesophageal  ganglia — i.e.  the  nervous  centres  correspond- 
ing to  our  brain. 

But  what  kind  and  degree  of  power  must  such  olfactory 
organs  possess  1  The  dog  has,  relatively  to  the  rest  of  his 
brain,  a  much  greater  development  of  the  olfactory  nerves  and 
ganglia  than  man  has.  His  powers  of  smell  are  so  much 

greater  than  ours  that  we  find  it  difficult  to  conceive  the  possi- 
ility  of  what  we  actually  see  him  do.  As  an  example  I  may 
describe  an  experiment  I  made  upon  a  bloodhound  of  the 
famous  Cuban  breed.  He  belonged  to  a  friend  whose  house  is 
situated  on  an  eminence  commanding  an  extensive  view.  I 
started  from  the  garden  and  wandered  about  a  mile  away, 
crossed  several  fields  by  sinuous  courses,  climbing  over  stiles, 
and  jumping  ditches,  always  keeping  the  house  in  view  ;  I 
then  returned  by  quite  a  different  track.  The  bloodhound  was 
set  upon  the  beginning  of  my  track.  I  watched  him  from 
a  window  galloping  rapidly,  and  following  all  its  windings 
without  the  least  halting  or  hesitation.  It  was  as  clear  to  his 
nose  as  a  gravelled  path  or  a  luminous  streak  would  be  to  our 
eyes.  On  his  return  I  went  down  to  him,  and  without 
approaching  nearer  than  five  or  six  yards  he  recognized  me  as 
the  object  of  his  search,  proving  this  by  circling  round  me, 
baying  deeply  and  savagely  though  harmlessly,  as  he  always 
kept  at  about  the  same  distance.* 

*  "What  did  he  smell  ?  Was  it  an  emanation  from  the  soles  of  my 
feet?  If  so,  how  did  this  aura  get  through  the  soles  of  my  boots, 
which  were  thick  ?  It  could  scarcely  have  been  the  odor  of  the  boot 
soles  themselves  that  he  followed,  as  he  recognized  me  afterward  at 
some  distance.  This  suggests  an  interesting  experiment,  that  any- 
body owning  one  of  these  dogs  may  easily  try.  Make  a  similar  track 
to  mine,  but  when  on  the  way,  take  off  the  boots  you  wore  on  start- 
ing and  change  them  for  some  one  else's  boots,  or  a  new  pair,  and 
watch  the  result  from  the  window. 


14  SCIENCE  IN   SHORT   CHAPTERS. 

If  the  difference  of  development  between  the  human  and 
canine  internal  antennre  produces  all  this  difference  of  func- 
tion, what  a  gulf  may  there  be  between  our  powers  of  perceiv- 
ing material  emanations  and  those  possessed  by  insects  !  If 
my  anatomical  hypothesis  is  correct,  some  insects  have  protrud- 
ing nasal  organs  or  out- thrust  olfactory  nerves  as  long  as  all  the 
rest  of  their  bodies.  The  power  of  movement  of  these  in  all 
directions  afford  the  means  of  sensory  communication  over  a 
corresponding  range,  instead  of  being  limited  merely  to  the 
direction  of  the  nostril  openings.  In  some  insects,  such  as  the 
plumed  gnat,  the  antenna?  do  not  appear  to  be  thus  movable, 
but  this  want  of  mobility  is  more  than  compensated  by  the 
multitude  of  branchings  of  these  wonderful  organs,  whereby 
they  are  simultaneously  exposed  in  every  direction.  This 
structure  is  analogous  to  the  fixed  but  multiplied  eyes  of 
insects,  which,  by  seeing  all  round  at  once,  compensate  for  the 
want  of  that  mobility  possessed  by  others  that  have  but  a  single 
eyeball  mounted  on  a  flexible  and  mobile  stalk  ;  that  of  the 
spider,  for  example. 

Such  an  extension  of  such  a  sensory  function  is  equivalent  to 
living  in  another  world  of  which  we  have  no  knowledge  and 
can  form  no  definite  conception.  We,  by  our  senses  of  touch 
and  vision,  know  the  shapes  and  colors  of  objects,  and  by  our 
very  rudimentary  olfactory  organs  form  crude  ideas  of  their 
chemistry  or  composition,  through  the  medium  of  their  mate- 
rial emanations  ;  but  the  huge  exaggeration  of  this  power  in 
the  insect  should  supply  him  with  instinctive  perceptive 
powers  of  chemical  analysis,  a  direct  acquaintance  with  the 
inner  molecular  constitution  of  matter  far  clearer  and  deeper 
than  we  are  able  to  obtain  by  all  the  refinements  of  laboratory 
analyses  or  the  hypothetical  formulating  of  molecular  mathe- 
maticians. Add  this  to  the  other  world  of  sensations  produci- 
ble by  the  vibratory  movements  of  matter  lying  between  tho?o 
perceptible  by  our  organs  of  hearing  and  vision,  then  strain 
your  imagination  to  its  cracking  point,  and  you  will  still  fail  to 
picture  the  wonderland  in  which  the  smallest  of  our  fellow-, 
creatures  may  be  living,  moving,  and  having  their  being. 


CHAPTER  II. 

CONCERT-ROOM    ACOUSTICS. 

THE  acoustics  of  public  buildings  are  now  occupying  con- 
siderable attention  in  London.  The  vast  audiences  which  any 
kind  of  sensational  performance  in  the  huge  metropolis  is 
capable  of  attracting,  is  forcing  the  subject  upon  all  who  cater 
for  public  amusement  or  instruction.  There  was  probably  no 
building  in  London,  or  anywhere  else,  more  utterly  unfit  for 
musical  performances  than  the  Crystal  Palace  in  its  original 
condition  ;  but,  nevertheless,  the  Handel  Festival  of  last  week 
was  a  great  success.  I  attended  the  first  of  these  immense 
gatherings,  and  this  last  ;  but  nothing  of  the  kind  interme- 
diate, and,  therefore,  am  the  better  able  to  make  comparisons. 

My  recollections  of  the  first  were  so  very  unsatisfactory  that 
I  gladly  evaded  the  grand  rehearsal  of  Friday  week,  and  went  to 
the  "  Messiah"  on  Monday  with  an  astronomical  treatise  in 
my  pocket,  in  order  that  my  time  should  not  be  altogether 
wasted.  Being  seated  at  the  further  end  of  the  transept,  in  a 
gallery  above  the  level  of  the  general  ridge-and-f urrow  roof  of 
the  nave,  the  plump  little  Birmingham  tenor,  who  rose  to  sing 
the  first  solo,  appeared,  under  the  combined  optical  conditions 
of  distance  and  vertical  foreshortening,  like  a  chubby  cheese- 
mite  viewed  through  a  binocular  microscope.  Taking  it  for 
granted  that  his  message  of  comfort  could  not  possibly  reach 
my  ear,  I  determined  to  anticipate  the  exhortation  by  settling 
down  for  a  comfortable  reading  of  a  chapter  or  two,  but  was 
surprised  to  find  I  could  hear  every  note,  both  of  recitative  and 
air. 

It  thus  became  obvious  that  the  alterations  that  have  gradu- 
ally grown  since  the  time  when  Clara  Novello's  voice  was  the 
only  one  that  could  be  heard  across  the  transept  are  worthy  of 
study  ;  that  the  advertised  success  of  the  "  velarium"  is 
something  more  than  mere,  puffery.  I  accordingly  used  my 
eyes  as  well  as  my  ears,  and  made  a  few  notes  which  may  be 
interesting  to  musical  and  architectural,  as  well  as  to  scientific 
readers. 

Sound,   like    light,   heat,   and   all  other  radiations,   loses  its 


16  SCIENCE   IN   SHORT   CHAPTERS. 

intensity  as  it  is  outwardly  dispersed,  is  enfeebled  in  the  ratio 
of  the  squares  of  distance  ;  thus  at  twenty  feet  from  the  singer 
the  Joudness  of  the  sound  is  one  fourth  of  that  at  ten  feet,  at 
thirty  feet  one  ninth,  at  forty  feet  one  sixteenth,  at  fifty  feet 
one  twenty-fifth,  and  so  on  ;  that  is,  supposing  the  singer  or 
other  source  of  sound  is  surrounded  on  all  sides  by  free,  open, 
and  still  air. 

But  this  condition  is  never  fulfilled  in  practice,  excepting, 
perhaps,  by  Simeon  Stylites  when  he  preached  to  the  multitude 
from  the  top  of  his  column.  If  Mr.  Vernon  Rigby  had  stood 
on  the  top  of  one  of  his  native  South  Staffordshire  chimney- 
shafts,  of  the  same  height  above  the  ground  as  the  Upper  Press 
Gallery  of  the  Crystal  Palace  is  above  the  front  of  the  orches- 
tra, and  I  had  stood  on  the  open  ground  at  the  same,  distance 
away  and  below  him,  his  solo  of  "  Comfort  ye,  my  People" 
would  have  been  utterly  inaudible. 

What,  then,  is  the  reason  of  this  great  difference  of  effect  at 
,equal  distances  ?  If  we  can  answer  this  question,  we  shall 
know  something  about  the  acoustics  of  conceit  rooms. 

The  uninitiated  reader  will  at  once  begin  by  saying  that 
"  sound  rises."  This  is  almost  universally  believed,  and  yet,  it 
is  a  great  mistake,  as  commonly  understood.  Sound  radiates 
equally  in  every  direction — downward,  upward,  north,  south, 
east,  or  west,  unless  some  special  directive  agency  is  used. 
The  directive  agency  commonly  used  is  a  reflecting  or  rever- 
berating surface. 

Thus  the  voice  of  the  singer  travels  forward  more  abundantly 
than  backward,  because  he  uses  the  roof,  and,  to  some  extent, 
the  walls  and  floor  of  his  mouth,  as  a  sound  reflector.  The 
roof  of  his  mouth  being  made  of  concave  plates  of  bone  with  a 
thin  velarium  of  integument  stretched  tightly  over  them,  sup- 
plies a  model  sound  reflector  ;  and  I  strongly  recommend 
every  architect  who  has  to  build  a  concert  or  lecture  room,  or 
theatre,  to  study  the  roof  of  his  own  mouth,  and  imitate  it  as 
nearly  as  he  can  in  the  roof  of  his  building. 

The  great  Italian  singing  masters  of  the  old  school,  who, 
like  the  father  of  Persian!,  could  manufacture  a  great  voice  out 
of  average  raw  material,  studied  the  physiology  of  the  vocal 
organs,  and  one  of  their  first  instructions  to  their  pupils  was 
that  they  should  sing  against  the  roof  of  the  mouth,  then 
throw  the  head  back  and  open  the  mouth,  so  that  the  sound 
should  reverberate  forward,  clear  of  the  teeth  and  lips.  For 
the  first  year  or  two  the  pupil  had  to  sing  only  "  la,  la,"  for 


COKCERT-ROOM   ACOUSTICS.  17 

several  hours  per  day,  until  the  faculty  of  doing  this  effectu- 
ally and  habitually  was  acquired. 

The  popular  notion  that  sound  rises  has  probably  originated 
from  the  fact  that  in  all  our  common  experience  the  sounds  are 
produced  near  to  some  kind  of  floor,  which  reflects  the  sound 
upward,  and  thus  adds  the  reflected  sound  to  that  which  is 
directly  transmitted,  and  thereby  the  general  result  is  materi- 
ally augmented. 

But  if  we  would  economize  sound  most  effectively,  we  must 
have  not  only  a  reflecting  floor,  but  also  a  reflecting  roof  and 
reflecting  walls  on  all  sides  of  the  concert  room.  These  arc 
the  conditions  that  were  wanting  in  the  original  structure  of 
the  Crystal  Palace  transept,  for  then  the  sound  of  the  singer's 
voice  could  travel  upward  to  that  lofty  arch  and  sidewise  in 
all  directions,  almost  as  freely  as  in  the  open  air. 

This  defect  has  been  remedied  to  a  very  great  extent  by  the 
velarium  stretched  across  from  the  springing  of  the  great  arch 
of  glass  and  iron,  and  forming  a  ceiling  to  the  concert  room 
part  of  the  building.  Beside  this,  a  wall  of  drapery  is 
stretched  across  each  side  of  the  transept,  and  the  orchestra 
has  its  special  walls,  roof,  and  back.  There  are  other  minor 
arrangements  for  effecting  lateral  reverberation  ;  that  is,  for 
returning  the  sound  into  the  auditorium  proper  instead  of 
allowing  it  to  wander  feebly  throughout  the  building. 

The  general  result  of  these  arrangements  is  to  render  that 
portion  of  the  building  in  which  the  reserved  seats  are  placed 
a  really  luxurious  and  efficient  concert  room,  of  magnificent 
proportions ;  but,  very  unfortunately  and  inevitably,  these 
conditions,  which  are  so  favorable  for  the  happy  eight  or  nine 
thousand  who  can  afford  reserved  seats,  render  the  position  of 
the  other  half-dozen  thousand  outsiders  more  disappointing  and 
vexatious  than  ever.  For  my  own  part  I  would  rather  spend  a 
holiday  afternoon  in  the  mild  atmosphere  and  the  quiet, 
soothing  gloom  of  a  coal-pit  Than  be  teased  and  irritated 
by  a  strained  listening  to  the  indefinite  roar  of  a  grand 
choir,  and  the  occasional  dying  vibrations  of  Sims  Reeves' 
"top  A." 

I  have  in  the  above  advocated  reverberation  as  a  remedy  for 
diffusion  of  sound.  This  may,  perhaps,  appear  rather  startling 
to  some  musicians  who  have  a  well-founded  dread  of  echoes, 
and  who  read  the  words  echo  and  reverberation  as  synonymous. 
This  requires  a  little  explanation.  As  light  is  transmitted, 
reflected,  and  absorbed  in  the  same  manner  as  sound,  and  as 


18  SCIENCE   IN   SHORT   CHAPTERS. 

light  is  visible — or  rather,  renders  objects  visible — I  will  illus- 
trate my  meaning  by  means  of  light. 

Let  us  suppose  three  apartments  of  equal  size  and  same 
shape,  one  having  its  walls  covered  with  mirrors,  the  second 
with  white  paper,  and  the  third  with  black  woollen  cloth,  and  all 
lighted  with  central  chandeliers  of  equal  brilliancy.  The  first 
and  second  will  be  much  lighter  than  the  third,  but  they  will 
be  illuminated  very  differently. 

In  the  first,  there  will  be  a  repetition  of  chandeliers  in  the 
mirrored  walls,  each  wall  definitely  reflecting  the  image  of  each 
particular  light.  In  the  second  room  there  will  be  reflection 
also,  and  economy  of  light,  but  no  reflection  of  definite  images  ; 
the  apartment  will  appear  to  be  filled  with  a  general  and  well- 
diffused  luminosity,  rendering  every  object  distinctly  visible, 
and  there  will  be  no  deep  shadows  anywhere. 

In  scientific  language,  we  shall  have,  in  the  first  room,  regu- 
lar reflection  ;  in  the  second,  scattering  reflection  ;  in  the  third 
room-  we  should  have  comparative  gloom,  owing  to  the  absorp- 
tion of  the  light  by  the  black  cloth. 

We  may  easily  suppose  the  parallels  of  these  in  the  case  of 
sound.  If  the  velarium  and  side  walls  of  the  transept  and 
orchestra  were  made  of  sheet  iron,  or  smooth,  bare,  unbroken 
vibrating  wooden  boards,  we  should  have  a  certain  amount  of 
regular  reflection  of  sound  or  echo.  Just  as  we  should  see  the 
particular  lights  of  the  chandelier  reflected  in  the  first  room,  so 
should  we  hear  the  particular  notes  of  the  singer  or  player 
echoed  by  such  regularly  vibrating  walls  and  ceiling. 

If,  again,  the  velarium  and  side  drapery  of  the  transept  and 
orchestra  had  been  thick,  soft  woollen  cloths,  the  sound,  like  the 
light,  would  have  been  absorbed  or  "  muffled,"  and,  though 
very  clear,  it  would  be  weak  and  insufficient. 

The  reader  will  now  ask,  What,  then,  is  the  right  material 
for  such  velarium  and  walls  ?  I  cannot  pretend  to  say  what  is 
the  best  possible,  believing  that  it  has  yet  to  be  discovered. 
The  best  yet  known,  and  attainable  at  moderate  expense,  is 
common  canvas  or  calico,  washed  or  painted  over  with  a  mixt- 
ure of  size  and  lime,  or  other  attainable  material  that  will  fill 
up  the  pores  of  the  fabric,  and  give  it  a  moderately  smooth 
face  or  surface.  Thus  prepared,  it  is  found  to  reflect  sound, 
as  paper,  ground  glass,  etc.,  reflect  light  by  scattering  rever- 
beration, but  without  definite  echo. 

It  will  now  be  understood  how  the  velarium  acted  in  render- 
ing the  solos  so  clearly  audible  at  the  great  height  and  distance 


CONCERT-ROOM   ACOUSTICS.  19 

of  the  Upper  Press  Gallery.  Instead  of  being  wasted  by 
diffusion  in  the  great  vault  above,  they  were  stopped  and 
reflected  by  the  velarium,  but  not  so  reflected  as  to  produce 
disagreeable  repetition  notes,  just  audible  at  particular  points, 
as  the  lights  of  the  mirror  reflections  of  the  chandeliers  would 
be. 

Flat  surfaces  reflect  radially,  while  concave  surfaces  with 
certain  curves  reflect  sound,  light,  heat,  etc.  in  parallel  lines. 
The  walls  and  roof  of  a  music  hall  should  scatter  their  reflec- 
tions on  all  sides,  and,  therefore,  should  be  flat,  or  nearly  so,  * 
excepting  at  the  angles,  which  should  be  curved  or  hollowed. 
From  the  orchestra  the  sound  is  chiefly  required  to  be  project- 
ed forward  as  from  the  singer's  mouth  ;  and,  therefore,  an 
orchestra  should  have  curved  walls  and  roof. 

Space  will  not  permit  a  dissertation  here  on  the  particular 
curve  required.  This  has,  I  believe,  been  carefully  calculated 
in  constructing  the  Crystal  Palace  orchestra.  Viewed  from  a 
distance,  the  whole  orchestra  is  curiously  like  a  huge  wide- 
opened  mouth  that  only  requires  to  close  a  little  and  open  a 
little  more,  according  to  the  articulations  of  the  choir,  to  repre- 
sent the  vocal  effort  of  one  gigantic  throat. 

There  is,  I  think,  one  fault  in  the  shape  of  this  mouth.  It 
extends  too  far  laterally  in  proportion  to  its  perpendicular 
dimensions.  The  angles  of  the  rnouth  are  too  acute  ;  the 
choir  extends  too  far  on  each  side.  The  singers  should  be 
packed  more  like  those  of  the  Birmingham  Festival  Choir. 

There  is  an  acoustic  limit  to  the  magnitude  of  choirs. 
Sound  travels  at  about  1100  feet  per  second,  and  thus,  if  one 
of  the  singers  of  a  choir  is  110  feet  nearer  than  another  singer 
to  any  particular  auditor,  the  near  singer  will  be  heard  one 
tenth  of  a  second  before  the  more  distant,  though  they  actually 
sing  exactly  together.  In  rapid  staccato  passages  this  would 
produce  serious  confusion,  though  in  such  music  as  most  of 
Handel's  it  would  be  scarcely  observable. 

Some  observations  which  I  have  made  convince  me  that  the 
actual  choir  of  the  Handel  Festivals  has  reached,  if  not  exceed- 
ed, the  acoustic  limits  even  for  Handel's  music,  and  decidedly 
exceeds  the  limits  permissible  for  Mendelssohn  and  most  other 
composers. 

I  found  that  when  standing  on  the  floor  of  the  building  in 
front  of  the  orchestra,  and  on  one  side,  I  could  plainly  distin- 
guish the  wave  of  difference  of  time  duetto  the  travelling  of 
the  sound,  and  in  all  the  passages  which  required  to  be  taken  up 


20  SCIENCE   IX   SHORT   CHAPTERS. 

smartly  and  simultaneously  by  the  opposite  sides  of  the  choir, 
the  effect  was  very  disagreeable. 

This  defect,  however,  was  not  observable  from  the  Press 
Gallery,  which  is  placed  as  nearly  as  may  be  to  the  focus  of  the 
orchestral  curve,  so  that  radial  lines  drawn  from  the  auditor  to 
different  parts  of  the  orchestra  do  not  differ  so  much  in  length 
as  to  effect  perceptible  differences  in  the  moment  at  which  the 
different  sounds  reach  the  ear. 

My  conclusion,  therefore,  is  that  if  any  amendment  is  to  be 
made  in  the  numbers  of  the  Handel  Festival  choir,  it  should 
rather  be  done  by  a  reduction  than  an  increase  ;  that  the  four 
thousand  voices  should  rather  be  reduced  to  three  thousand 
than  increased  to  five  thousand.  With  greater  severity  of 
selection  as  regards  quality,  power,  and  training  of  each  indi- 
vidual voice,  and  with  better  packing,  the  three  thousand 
would  be  more  effective  than  the  four  thousand. 


CHAPTER  III. 

THE    ORIGIN    OF    SOAP. 

A  HISTORY  of  soap  would  be  very  interesting.  Who  invent- 
ed it  ?  When  and  where  did  it  first  come  into  common  use  ? 
How  did  our  remote  ancestors  wash  themselves  before  soap 
was  invented  ?  These  are  historical  questions  that  naturally 
arise  at  first  contemplation  of  the  subject  ;  but,  as  far  as  we  are 
aware,  historians  have  failed  to  answer  them.  We  read  a 
great  deal  in  ancient  histories  about  anointing  with  oil  and  the 
use  of  various  cosmetics  for  the  skin,  but  nothing  about  soap. 

These  ancients  must  have  been  very  greasy  people,  and  I 
suspect  that  they  washed  themselves  pretty  nearly  in  the  same 
way  as  modern  engine-drivers  clean  their  fingers,  by  wiping  off 
the  oil  with  a  bit  of  cotton-waste. 

We  are  taught  to  believe  that  the  ancient  Romans  wrapped 
themselves  round  with  togas  of  ample  dimensions,  and  that 
these  togas  were  white.  Now,  such  togas,  after  incasing  such 
anointed  oily  skins,  must  have  become  very  greasy.  How  did 
the  Roman  laundresses  or  launders — historians  do  not  indicate 
their  sex — remove  this  grease  ?  Historians  are  also  silent  on 
this  subject. 

A  great  many  curious  things  were  found  buried  under  the 
cinders  of  Vesuvius  in  Pompeii,  and  sealed  up  in  the  lava  that 
flowed  over  Herculaneum.  Bread,  wine,  fruits,  and  other 
domestic  articles,  including  several  luxuries  of  the  toilet,  such 
as  pomades  or  pomade-pots,  and  rouge  for  painting  ladies' 
faces,  but  no  soap  for  washing  them.  In  the  British  Museum 
is  a  large  variety  of  household  requirements  found  in  the  pyra- 
mids of  Egypt,  but  there  is  no  soap,  and  we  have  not  heard  of 
any  having  been  discovered  there. 

Finding  no  traces  of  soap  among  the  Romans,  Greeks,  or 
Egyptians,  we  need  not  go  back  to  the  prehistoric  "  cave  men,1' 
whose  flint  and  bone  implements  were  found  imbedded  side  by 
side  with  the  remains  of  the  mammoth  bear  and  hyena  in  such 
caverns  as  that  at  Torquay,  where  Mr.  Pengelly  has,  during 
the  last  eighteen  years,  so  industriously  explored. 

All  our  knowledge,  and  that  still  larger  quantity,  our  igno- 


22  SCIENCE   IK   SHORT   CHAPTERS. 

ranee,  of  the  habits  of  antique  savages,  indicate  that  solid 
soap,  such  as  we  commonly  use,  is  a  comparatively  modern 
luxury  ;  but  it  does  not  follow  that  they  had  no  substitute. 
To  learn  what  that  substitute  may  probably  have  been  we  may 
observe  the  habits  of  modern  savages,  or  primitive  people  at 
home  and  abroad. 

This  will  teach  us  that  clay,  especially  where  it  is  found  hav- 
ing some  of  the  unctuous  properties  of  fuller's  earth,  is  freely 
used  for  lavatory  purposes,  and  was  probably  used  by  the 
Romans,  who  were  by  no  means  remarkable  for  anything 
approaching  to  true  refinement.  They  were  essentially  a  nasty 
people,  the  habits  of  the  poor  being  4<  cheap  and  nasty"  ;  of 
the  rich,  luxurious  and  nasty.  The  Roman  nobleman  did  not 
sit  down  to  dinner,  but  sprawled  with  his  face  downward,  and 
took  his  food  as  modern  swine  take  theirs.  At  grand  banquets, 
after  gorging  to  repletion,  he  tickled  his  throat  in  order  to 
vomit  and  make  room  for  more.  He  took  baths  occasionally, 
and  was  probably  scoured  and  shampooed  as  well  as  oiled,  but 
it  is  doubtful  whether  he  performed  any  intermediate  domestic 
ablutions  worth  naming. 

A  refinement  upon  washing  with  clay  is  to  be  found  in  the 
practice  once  common  in  England,  and  still  largely  used  where 
wood  fires  prevail.  It  is  the  old-fashioned  practice  of  pouring 
water  on  the  wood  ashes,  and  using  the  "  lees"  thus  obtained. 
These  lees  are  a  solution  of  alkaline  carbonate  of  potash,  the 
modern  name  of  potash  being  derived  from  the  fact  that  it  was 
originally  obtained  from  the  ashes  under  the  pot.  In  like 
manner  soda  was  obtained  from  the  ashes  of  seaweeds  and  of 
the  plants  that  grow  near  the  sea-shore,  such  as  the  salsover 
soda,  etc. 

The  potashes  or  pearlashes  being  so  universal  as  a  domestic 
by-product,  it  was  but  natural  that  they  should  be  commonly 
used,  especially  for  the  washing  of  greasy  clothes,  as  they  are 
to  the  present  day.  Upon  these  facts  we  may  build  up  a 
theory  of  the  origin  of  soap. 

It  is  a  compound  of  oil  or  fat  with  soda  or  potash,  and 
would  be  formed  accidentally  if  the  fat  on  the  surface  of  the 
pot  should  boil  over  and  fall  into  the  ashes  under  the  pot. 
The  solution  of  such  a  mixture  if  boiled  down  would  give  us 
soft  soap. 

If  oil  or  fat  became  mixed  with  the  ashes  of  soda  plants,  it 
would  produce  hard  soap.  Such  a  mixture  would  most  easily 
be  formed  accidentally  in  regions  where  the  olive  flourishes 


THE   ORIGIX   OF   SOAP.  23 

near  the  coast,  as  in  Italy  and  Spain  for  example,  and  this  mixt- 
ure would  be  Castile  soap,  which  is  still  largely  made  by  com- 
bining refuse  or  inferior  olive  oil  with  the  soda  obtained  from 
the  ashes  of  seaweed. 

The  primitive  soap-maker  would,  however,  encounter  one 
difficulty — that  arising  from  the  fact  that  the  potash  or  soda 
obtained  by  simple  burning  of  the  wood  or  seaweed  is  more  or 
less  combined  with  carbonic  acid,  instead  of  being  all  in  the 
caustic  state  which  is  required  for  effective  soap-making.  The 
modern  soap-maker  removes  this  carbonic  acid  by  means  of 
caustic  lime,  which  takes  it  away  from  the  carbonate  of  soda 
or  carbonate  of  potash  by  simple  exchange — i.e.,  caustic  lime 
plus  carbonate  of  soda  becoming  caustic  soda  plus  carbonate  of 
lime,  or  carbonate  of  potash  plus  caustic  lime  becoming  caustic 
potash  plus  carbonate  of  lime. 

How  the  possibility  of  making  this  exchange  became  known 
to  the  primitive  soap-maker,  or  whether  he  knew  it  at  all, 
remains  a  mystery,  but  certain  it  is  that  it  was  practically  used 
long  before  the  chemistry  of  the  action  was  at  all  understood. 
It  is  very  probable  that  the  old  alchemists  had  a  hand  in  this. 

In  their  search  for  the  philosopher's  stone,  the  elixir  of  life 
or  drinkable  gold,  and  for  the  universal  solvent,  they  mixed 
together  everything  that  came  to  hand,  they  boiled  everything 
that  was  boilable,  distilled  everything  that  was  volatile,  burned 
everything  that  was  combustible,  and  tortured  all  their  "  sim- 
ples" and  their  mixtures  by  every  conceivable  device,  thereby 
stumbling  upon  many  curious,  many  wonderful,  and  many  use- 
ful results.  Some  of  them  were  not  altogether  visionary — 
were,  in  fact,  very  practical,  quite  capable  of  understanding 
the  action  of  caustic  lime  on  carbonate  of  soda,  and  of  turning 
it  to  profitable  account. 

It  is  not,  however,  absolutely  necessary  to  use  the  lime,  as 
the  soda  plants  when  carefully  burned  in  pits  dug  in  the  sand 
of  the  sea-shore  may  contain  but  little  carbonic  acid  if  the 
ash  is  fluxed  into  a  hard  cake  like  that  now  commonly  pro- 
duced, and  sold  as  "  soda  ash."  This  contains  from  3  to  30 
per  cent,  of  carbonate,  and  thus  some  samples  are  nearly  caus- 
tic, without  the  aid  of  lime. 

As  cleanliness  is  the  fundamental  basis  of  all  true  physical 
refinement,  it  has  been  proposed  to  estimate  the  progress  of 
civilization  by  the  consumption  of  soap,  the  relative  civiliza- 
tion of  given  communities  being  numerically  measured  by  the 
following  operation  in  simple  arithmetic  :  Divide  the  total 


24  SCIENCE   IN"   SHORT   CHAPTERS. 

quantity  of  soap  consumed  in  a  given  time  by  tlie  total  popu- 
lation consuming  it,  and  the  quotient  expresses  the  civilization 
of  that  community.* 

The  allusion  made  by  Lord  Beaconsfield,  at  the  Lord 
Mayor's  dinner  in  1879,  to  the  prosperity  of  our  chemical 
manufactures  was  a  subject  of  merriment  to  some  critics,  who 
are  probably  ignorant  of  the  fact  that  soap -making  is  a  chemical 
manufacture,  and  that  it  involves  many  other  chemical  manu- 
factures, some  of  them,  in  their  present  state,  the  results  of 
the  highest  refinements  of  modern  chemical  science. 

While  the  fishers  of  the  Hebrides  and  the  peasants  on  the 
shores  of  the  Mediterranean  are  still  obtaining  soda  by  burning 
seaweed  as  they  did  of  old,  our  chemical  manufacturers  are 
importing  sulphur  from  Sicily  and  Iceland,  pyrites  from  all 
quarters,  nitrate  of  soda  from  Peru  and  the  East  Indies,  for 
the  manufacture  of  sulphuric  acid,  by  the  aid  of  which  they 
now  make  enormous  quantites  of  caustic  soda  from  the  material 
extracted  from  the  salt  mines  of  Cheshire  and  Droitwich. 
These  sulphuric  acid  works  and  these  soda  works  are  among 
the  most  prosperous  and  rapidly  growing  of  our  manufactur- 
ing industries,  and  their  chief  function  is  that  of  ministering 
to  soap-making,  in  which  Britain  is  now  competing  triumphant- 
ly with  all  the  world. 

By  simply  considering  how  much  is  expended  annually  for 
soap  in  every  decent  household,  and  adding  to  this  the  quan- 
tity consumed  in  laundries  and  by  our  woollen  and  cotton 
manufacturers,  a  large  sum  total  is  displayed.  Formerly,  we 
imported  much  of  the  soap  we  used  at  home  ;  now,  in  spite  of 
our  greatly  magnified  consumption,  we  supply  ourselves  with 
all  but  a  few  special  kinds,  and  export  very  large  and  continu- 
ally increasing  quantities  to  all  parts  of  the  world  ;  and  if  the 
arithmetical  rule  given  above  is  sound,  the  demand  must  stead- 
ily increase  as  civilization  advances. 

*  The  scientific  pedant  of  the  Middle  Ages  displayed  his  profundi- 
ty by  continually  quoting  Ajristotle  and  other  "  ancients."  His  mod- 
ern successor  does  the  like  by  decorating  his  pages  with  displays  of 
algebraical  formula.  In  order  to  secure  the  proper  respect  of  my 
readers  I  here  repeat  the  equation  that  I  enunciated  many  years  ago, 
"  c  =  -"  where  c  stands  for  civilization,  s  for  the  quantity  of  soap  con- 
sumed per  annum,  and  p  the  population  of  a  given  community. 


CHAPTER  IV. 

OILING    THE    WAVES. 

THE  recent  gales  have  shown  that  if  "  Britannia  rules  the 
waves"  her  subjects  are  very  turbulent  and  costly.  Our  ship- 
ping interests  are  now  of  enormous  magnitude,  and  they  are 
growing  year  by  year.  We  are,  in  fact,  becoming  the  world's 
carriers  on  the  ocean,  and  are  thus  ruling  the  waves  in  a  far 
better  sense  than  in  the  old  one.  Our  present  mercantile  rule 
adds  to  the  wealth  of  our  neighbors,  instead  of  destroying  it, 
as  under  the  old  warlike  rule. 

Everything  concerning  these  waves  is  thus  of  great  national 
interest,  the  loss  of  life  and  sacrifice  of  wealth  by  marine 
casualties  being  so  great.  Some  curious  old  stories  are  extant, 
describing  the  exploits  of  ancient  mariners  in  stilling  the  waves 
by  pouring  oil  upon  them.  Both  Plutarch  and  Pliny  speak  of 
it  as  a  regular  practice.  Much  later  than  this,  in  a  letter  dated 
Batavia,  January  5th,  1770,  written  by  M.  Tengragel,  and 
addressed  to  Count  Bentinck,  the  following  passage  occurs  : 
**  Near  the  islands  Paul  and  Amsterdam  we  met  with  a  storm, 
which  had  nothing  particular  in  it  worthy  of  being  communi- 
cated to  you,  except  that  the  captain  found  himself  obliged, 
for  greater  safety  in  wearing  the  ship,  to  pour  oil  into  the  sea 
to  prevent  the  waves  breaking  over  her,  which  had  an  excellent 
effect,  and  succeeded  in  preserving  us.  As  he  poured  out  but 
a  little  at  a  time,  the  East  India  Company  owes,  perhaps,  its 
ship  to  only  six  demi-aumes  of  olive  oil.  I  was  present  on 
deck  when  this  was  done,  and  should  not  have  mentioned  this 
circumstance  to  you,  but  that  we  have  found  people  here  so 
prejudiced  against  the  experiment  as  to  make  it  necessary  for 
the  officers  on  board  and  myself  to  give  a  certificate  of  the 
truth  on  this  head,  of  which  we  made  no  difficulty." 

The  idea  was  regarded  with  similar  prejudice  by  scientific 
men  until  Benjamin  Franklin  had  his  attention  called  to  it,  as 
he  thus  narrates  :  "In  1757,  being  at  sea  in  a  fleet  of  ninety- 
six  sail,  bound  for  Louisburg,  I  observed  the  wakes  of  two  of 
the  ships  to  be  remarkably  smooth,  while  all  the  others  were 
ruffled  by  the  wind,  which  blew  fresh.  Being  puzzled  with 


26  SCIENCE   IN   SHORT   CHAPTERS. 

the  differing  appearance,  I  at  last  pointed  it  out  to  the  captain, 
and  asked  him  the  meaning  of  it.  *  The  cooks,'  said  he, 
1  have,  I  suppose,  been  just  emptying  their  greasy  water 
through  the  scuppers,  which  has  greased  the  sides  of  the  ships 
a  little.'  And  this  answer  he  gave  me  with  an  air  of  some 
little  contempt,  as  to  a  person  ignorant  of  what  everybody  else 
knew.  In  my  own  mind,  I  first  slighted  the  solution,  though 
I  was  not  able  to  think  of  another." 

Franklin  was  not  a  man  to  remain  prejudiced  ;  he  accord- 
ingly investigated  the  subject,  and  the  results  of  his  experi- 
ments, made  upon  a  pond  on  Clapham  Common,  were  com- 
municated to  the  Royal  Society.  He  states  that,  after  drop- 
ping a  little  oil  on  the  water,  "  I  saw  it  spread  itself  with  surpris- 
ing swiftness  upon  the  surface,  but  the  effect  of  smoothing  the 
waves  was  not  produced  ;  for  I  had  applied  it  first  upon  the 
leeward  side  of  the  pond,  where  the  waves  were  largest,  and 
the  wind  drove  my  oil  back  upon  the  shore.  I  then  went  to 
the  windward  side,  where  they  began  to  form  ;  and  there  the 
oil,  though  not  more  than  a  teaspoonful,  produced  an  instant 
calm  over  a  space  several  yards  square,  which  spread  amazingly, 
and  extended  itself  gradually  till  it  reached  the  lee  side,  mak- 
ing all  that  quarter  of  the  pond  (perhaps  half  an  acre)  as 
smooth  as  a  looking-glass." 

Franklin  made  further  experiments  at  the  entrance  of  Ports- 
mouth Harbor,  opposite  the  Haslar  Hospital,  in  company  with 
Sir  Joseph  Banks,  Dr.  Blagden,  and  Dr.  Solander.  In  these 
experiments  the  waves  were  not  destroyed,  but  were  converted 
into  gentle  swelling  undulations  with  smooth  surfaces.  Thus 
it  appeared  that  the  oil  destroys  small  waves,  but  not  large 
billows. 

Franklin's  explanation  is,  "  that  the  wind  blowing  over 
water  covered  with  a  film  of  oil  cannot  easily  catch  upon  it,  so 
as  to  raise  the  first  wrinkles,  but  slides  over  it  and  leaves  it 
smooth  as  it  finds  it." 

Further  investigations  have  since  been  made  which  confirm 
this  theory.  The  first  action  of  the  wind  in  blowing  up  what  ( 
the  sailors  call  "  a  sea,"  is  the  production  of  a  ripple  on  the 
surface  of  the  water.  This  ripple  gives  the  wind  a  strong  hold, 
and  thus  larger  waves  are  formed,  but  on  these  larger  there  are 
smaller  waves,  and  on  these  smaller  waves  still  smaller  ripples. 
All  this  roughness  of  surface  goes  on  helping  the  wind,  till  at 
last  the  mightiest  billows  are  formed,  which  then  have  an 
oscillation  independent  of  the  wind  that  formed  them.  Hence 


OILIXG   THE   WAVES.  27 

the  oil  cannot  at  once  subdue  the  great  waves  that  are  already 
formed,  but  may  prevent  their  formation  if  applied  in  time. 
Even  the  great  waves  are  moderated  by  the  oil  stopping  the 
action  of  the  wind  which  sustains  and  augments  them. 

Quite  recently,  Captain  David  Gray  made  some  experiments 
at  the  north  bar  of  Peterhead,  where  a  very  heavy  surf  breaks 
over  in  rough  weather.  On  a  rough  day  he  dropped  a  bottle 
full  of  oil  into  the  sea.  The  oil,  floating  out  of  the  bottle, 
converted  the  choppy  waves  over  a  large  area  "  into  an 
expanse  of  long  undulating  rollers,  smooth  and  glassy,  and  so 
robbed  of  all  violence  that  a  small  open  boat  could  ride  on 
them  in  safety/' 

This  result  is  quite  in  accordance  with  what  we  are  told 
respecting  the  ancient  practice  of  the  fishermen  of  Lisbon,  who 
were  accustomed  to  empty  a  bottle  of  oil  into  the  sea  when 
they  found  on  their  return  to  the  river  that  there  was  a  danger- 
ous surf  on  the  bar,  which  might  fill  their  boats  in  crossing  it. 

As  regards  Peterhead,  it  is  proposed  to  lay  perforated  pipes 
across  the  mouth  of  the  harbor,  and  to  erect  tanks  from  which 
these  pipes  may  be  supplied  with  oil,  and  thus  pour  a  contin- 
uous and  widely  distributed  stream  into  the  sea  in  bad  weather. 
The  scheme  was  mooted  some  time  ago,  but  I  am  not  aware 
whether  it  has  yet  been  carried  out.  Its  success  or  failure 
must  mainly  be  determined  by  the  cost,  and  this  will  largely 
depend  upon  the  kind  of  oil  that  is  used.  A  series  of  well- 
conducted  experiments  upon  the  comparative  areas  protected 
by  different  kinds  of  oil  would  be  very  interesting  and  practi- 
cally useful,  for  until  this  has  been  ascertained,  a  proper 
selection  cannot  be  made.  How  long  will  it  last  ?  is  another 
question. 

I  have  frequently  seen  such  tracks  as  Franklin  observed  out 
at  sea,  and  have  climbed  to  the  masthead  in  order  to  sight 
the  ship  that  produced  them  without  seeing  any.  Several  of 
such  smooth  shining  tracks  have  been  observed  at  the  same 
time,  but  no  ship  visible,  and  this  in  places  where  no  sail  has 
been  seen  for  days  before  or  after.  The  poet's  description  of- 
"  the  trackless  ocean"  is  by  no  means  "  founded  on  fact." 

The  Plymouth  Breakwater  contains  3,369,261  tons  of  stone, 
and  cost  the  British  Government  a  million  and  a  half.  The 
interest  on  this  at  4  per  cent,  amounts  to  £60,000  per  annum. 
If  the  above  statements  are  reliable,  some  of  the  wholesale  oil 
merchants  who  read  this  might  contract  to  becalm  a  consider- 
able area  of  the  Channel  for  a  smaller  amount. 


28  SCIENCE    IX    SHORT   CHAPTERS. 

Further  experiments  have  been  made  at  Peterliead  since  the 
above  was  written.  The  following  account,  from  the  Times, 
of  those  made  on  February  27th,  1882,  is  interesting  : 

"  On  Monday  the  long-wished-for  easterly  gale  to  test  the 
experiment  of  throwing  oil  on  the  troubled  waters  reached 
Peterliead.  It  may  be  mentioned  that  the  Harbor  of  Peter- 
head  is  singularly  exposed,  and  with  an  east  or  north-east  gale 
is  very  dangerous  of  approach.  Mr.  Shields,  of  Perth,  has  laid 
the  oil  apparatus  to  be  used  in  quelling  the  troubled  waters. 

;  It  consists  of  an  iron  pipe  which  conveys  oil  and  extends  from 
a  wooden  house  behind  the  sea-wall  at  Roanhead  down 
through  a  natural  gullet  in  the  rocks  about  150  yards  long  and 
about  50  yards  beyond  the  mouth  of  the  gullet  into  about 
seven  fathoms  of  water  ;  at  this  point  the  iron  pipe  is  joined 
to  a  gutta-percha  pipe,  which  'extends  across  the  harbor 
entrance  outside  the  bar  and  is  perforated  at  distances  12-£ 
yards  apart.  Through  the  gutta-percha  pipe  the  oil  reaches  the 
sea.  On  Monday  the  wind  was  not  so  strong  as  to  make  the 
experiment  so  complete  as  could  have  been  wished  ;  still  there 
was  a  heavy  swell.  Early  in  the  forenoon  the  pumps  were 
put  in  motion  and  the  leakage  space  in  the  pipe  filled  ;  but 
unfortunately  it  was  found,  soon  after  the  oil  began  to  rise  to 
the  surface  of  the  bay,  that  the  supply  in  the  cask  had  become 
exhausted,  and  those  who  were  conducting  the  experiment  did 
not  consider  themselves  at  liberty  to  order  a  fresh  cask  of  oil 
without  Mr.  Shields's  sanction.  But  while  the  experiment  was 
only  partial  it  was  highly  satisfactory.  At  the  same  time,  the 
film  did  not  extend  sufficiently  far  to  prevent  the  waves  form- 
ing and  curving  to  broken  water.  As  soon,  however,  as  they 
reached  the  oil -covered  neck  the  observers  from  the  pier-head 
could  easily  discern  the  influence  at  work.  Waves  which 
came  in  crested  gradually  assumed  the  shape  of  undulating 
bodies  of  water,  and,  once  formed,  they  rolled  unbroken 
toward  the  breakwater.  On  Wednesday  morning  there  was 
a  heavy  sea  at  the  north  breakwater.  The  oil  valves  were 
'opened,  and  immediately  the  effect  was  manifest.  The  waves, 

i  which  had  before  dashed  with  fury  against  the  breakwater, 
assumed  a  rolling  motion,  and  were  quite  crestless.  Indeed, 
it  was  admitted  that  the  oil  had  rendered  the  entrance  com- 
paratively safe,  but  the  effect  was  not  so  abiding  as  could  have 
been  wished." 

As  regards  the  want  of  duration  there  noted,  I  venture  to 
make  a  suggestion. 


OILING  THE   WAVES.  29 

Oils  vary  so  greatly  in  their  rate  of  outspreading  over  water 
and  the  character  of  the  film  they  form,  that  some  years  ago 
Mr.  Moffatt,  of  Glasgow,  proposed  to  use  these  differences  as 
a  test  for  the  adulterations  of  one  kind  of  oil  with  other  and 
cheaper  kinds. 

I  made  a  number  of  experiments,  verifying  some  of  his 
results. 

From  these  it  is  evident  that  the  duration  of  the  becalming 
effect  will  vary  with  different  oils,  and  therefore  further 
experiments  upon  these  differences  should  be  made,  in  order 
to  select  that  kind  which  is  the  most  effective,  with  due 
regard,  of  course,  to  cost. 

The  oil  indicated  by  my  experiments  as  combining  perma- 
nency and  cheapness,  and  altogether  the  most  suitable  and 
attainable,  is  the  "  dead  oil"  refuse  of  the  gas-works.  This 
may  be  used  in  its  crude  and  cheapest  condition. 


CHAPTER  V. 

THE    ACTION    OF    FROST    IN    WATER-PIPES     AND    ON    BUILDING 
MATERIALS. 

POPULAR  science  has  penetrated  too  deeply  now  to  render 
necessary  any  refutation  of  the  old  popular  fallacy  which  at- 
tributed the  bursting  of  water-pipes  to  the  thaw  following  a 
frost  ;  everybody  now  understands  that  the  thaw  merely 
renders  the  work  of  the  previous  freezing  so  disastrously  evi- 
dent. Nevertheless,  the  general  subject  of  the  action  of  freez- 
ing water  upon  our  dwellings  is  not  so  fully  understood  by  all 
concerned  as  it  should  be.  Builders  and  house-owners  should 
understand  it  thoroughly,  as  most  of  the  domestic  miseries 
resulting  from  severe  winters  may  be  greatly  mitigated,  if  not 
entirely  prevented,  by  scientific  adaptation  in  the  course  of 
building  construction.  Nowadays  tenants  know  something 
about  this,  and  select  accordingly.  Thus  the  market  value  of  a 
building  may  be  increased  by  such  adaptation. 

Solids,  liquids,  and  gases  expand  as  they  are  heated.  This 
great  general  law  is,  however,  subject  to  a  few  exceptions,  the 
most  remarkable  of  which  is  that  presented  by  water.  Let  us 
suppose  a  simple  experiment.  Imagine  a  thermometer  tube 
with  its  bulb  and  stem  so  filled  with  water  that  when  the  water 
is  heated  nearly  to  its  boiling  point  it  will  rise  to  nearly  the 
top  of  the  long'  stem.  Now  let  us  cool  it.  As  the  cooling 
proceeds  the  wTater  will  descend,  and  this  descending  will  con- 
tinue until  it  attains  the  temperature  marked  on  our  ordinary 
thermometer  as  39°,  or  more  strictly  39^;  then  a  strange  in- 
version occurs.  As  the  temperature  falls  below  this,  the  water 
rises  gradually  in  the  stem  until  the  freezing  point  is  reached. 

This  expansion  amounts  to  -^Vs"  Par^  °^  ^ne  WD0^e  bulk  °^ 
the  water,  or  100,000  parts  become  100,013.  So  far  the 
amount  of  expansion  is  very  small,  but  this  is  only  a  foretaste 
of  what  is  coming.  Lowering  the  temperature  still  further, 
the  water  begins  to  freeze,  and  at  the  moment  of  freezing  it 
expands  suddenly  to  an  extent  equalling  -^  of  its  bulk,  i.e.  of 
the  bulk  of  so  much  water  as  becomes  solidified.  The  temper- 
ature remains  at  32°  until  the  whole  of  the  water  is  frozen. 


THE   ACTION   OF   FROST   IX   WATER-PIPES.  31 

Fortunately  for  us,  the  freezing  of  water  is  always  a  slow 
process,  for  if  this  conversion  of  every  15  gallons  into  16  took 
place  suddenly,  all  our  pipes  would  rip  open  with  something 
like  explosive  violence.  But  such  sudden  freezing  of  any 
considerable  quantity  of  water  is  practically  impossible,  on 
account  of  the  "  latent  heat"  of  liquid  water,  which  amounts 
to  142£°.  All  this  is  given  out  in  the  act  of  freezing.  It  is 
this  giving  out  of  so  much  heat  that  keeps  the  temperature  of 
freezing  water  always  at  32%  even  though  the  air  around  may 
be  much  colder.  No  part  of  the  water  can  fall  below  32° 
without  becoming  solid,  and  that  portion  which  solidifies 
gives  out  enough  heat  to  raise  142^  times  its  own  quantity 
from  31°  to  32°. 

The  slowness  of  thawing  is  due  to  the  same  general  fact. 
An  instructive  experiment  may  be  made  by  simply  filling  a 
saucepan  with  snow  or  broken  ice,  and  placing  it  over  a  com- 
mon fire.  The  slowness  of  the  thawing  will  surprise  most 
people  who  have  not  previously  tried  the  experiment.  It  takes 
about  as  long  to  melt  this  snow  as  it  would  to  raise  an 
equal  weight  of  water  from  32°  to  174°.  Or,  if  a  pound  of 
water  at  174°  be  mixed  with  a  pound  of  snow  at  32°,  the  result 
will  be  two  pounds  of  water  at  32° ;  142°  will  have  disap- 
peared without  making  the  snow  any  warmer,  it  will  all  have 
been  used  up  in  doing  the  work  of  melting. 

The  force  with  which  the  great  expansion  due  to  freezing 
takes  place  is  practically  irresistible.  Strong  pieces  of 
ordnance  have  been  filled  with  water,  and  plugged  at  muzzle 
and  touch-hole.  They  have  burst  in  spite  of  their  great  thick- 
ness and  tenacity.  Such  being  the  case,  it  is  at  first  sight  a  mat- 
ter of  surprise  that  frozen  water-pipes,  whether  of  lead  or  iron, 
ever  stand  at  all.  They  would  not  stand  but  for  another  property 
of  ice,  which  is  but  very  little  understood — viz.  its  viscosity. 

This  requires  some  explanation.  Though  ice  is  what  we  call 
a  solid,  it  is  not  truly  solid.  Like  other  apparent  solids  it  is 
not  perfectly  rigid,  but  still  retains  some  degree  of  the  possi- 
bility of  flowing  which  is  the  characteristic  of  liquids.  This 
has  been  shown  by  filling  a  bombshell  with  water,  leaving  the 
fuse-hole  open  and  freezing  it.  A  shell  of  ice  is  first  formed 
on  the  outside,  which  of  course  plugs  up  the  fuse-hole.  Then 
the  interior  gradually  freezes,  but  the  expansion  due  to  this 
forces  the  ice  out  of  the  fuse-hole  as  a  cylindrical  stick,  just 
as  putty  might  be  squeezed  out,  only  that  the  force  required  to 
mould  and  eject  the  ice  is  much  greater. 


32  SCIENCE   IN   SHORT   CHAPTERS. 

I  have  constructed  an  apparatus  which  illustrates  this  very 
strikingly.  It  is  an  iron  syringe  with  a  cylindrical  interior  of 
about  half  an  inch  in  diameter,  and  a  terminal  orifice  of  less 
than  T^-g.  of  an  inch  in  diameter.  Its  piston  of  metal  is  driven 
down  by  a  screw.  Into  this  syringe  I  place  small  fragments 
of  ice,  or  a  cylinder  of  ice  fitted  to  the  syringe,  and  then 
screw  down  the  piston.  Presently  a  thin  wire  of  ice  is 
squirted  forth  like  vermicelli  when  the  dough  from  which  it  is 
made  is  similarly  treated,  showing  that  the  ice  is  plastic  like 
the  dough,  provided  it  is  squeezed  with  sufficient  force. 

The  viscosity  of  ice  is  displayed  on  a  grand  scale  in  glaciers, 
the  ice  of  which  actually  flows  like  a  river  down  the  glacier 
valley,  contracting  as  the  valley  narrows  and  spreading  out  as 
it  widens,  just  as  a  river  would  ;  but  moving  only  a  few  inches 
daily  according  to  the  steepness  of  the  slope  and  the  season, 
slower  in  winter  than  in  summer. 

Upon  this,  and  the  slowness  of  the  act  of  freezing,  depends 
the  possibility  of  water  freezing  in  iron  pipes  without  bursting 
them.  Even  iron  yields  a  little  before  bursting,  but  ordinary 
qualities  not  sufficiently  to  bear  the  expansion  of  -fa  of  their 
contents.  What  happens,  then  ?  The  cylinder  of  ice  con- 
tained in  the  tube  elongates  as  it  freezes,  provided  always  the 
pipe  is  open  at  one  or  both  ends.  But  there  is  a  limit  to  this, 
seeing  that  the  friction  of  such  a  tight-fitting  core,  even  of 
slippery  ice,  is  considerable,  and  if  the  pipe  be  too  long,  the 
resistance  of  this  friction  may  exceed  the  resistance  of  tenacity 
of  the  pipe.  I  am  unable  to  give  any  figures  for  such  length  ; 
the  subject  does  not  appear  to  have  been  investigated  as  it 
should  be,  and  as  it  might  well  be  by  our  wealthy  water  com- 
panies. 

We  all  know  that  lead  pipes  frequently  succumb,  but  a  little 
observation  shows  that  they  do  so  only  after  a  struggle.  The 
tenacity  of  lead  is  much  less  than  that  iron  (about  ^  of  that 
of  ordinary  wrought  iron),  but  it  yields  considerably  before 
breaking.  It  has,  in  fact,  the  property  of  viscosity  similar  to 
that  of  ice.  At  Woolwich  the  lead  used  for  elongated  rifle 
bullets  is  squirted  like  the  ice  in  my  syringe  above  described, 
powerful  hydraulic  pressure  being  used. 

This  yielding  saves  many  pipes.  It  would  save  all  new  pipes 
if  the  lead  were  pure  and  uniform  ;  but  as  this  is  not  the  case, 
they  may  burst  at  a  weak  place,  the  yielding  being  shown  by 
the  bulge  that  commonly  appears  at  the  broken  part. 

From  the  above   it  may   bo   easily  understood  that  a  pipe 


THE   ACTION    OF   FROST.  IN    WATER-PIPES.  33 

\vhich  is  perfectly  cylindrical — other  conditions  equal — will  be 
less  likely  to  burst  than  one  which  is  of  varying  diameter,  as 
the  sliding  from  a  larger  to  a  smaller  portion  of  the  pipe  must 
be  attended  with  great  resistance,  or  a  certain  degree  of  block, 
beyond  what  would  be  due  to  the  mere  friction  along  a  pipe 
of  uniform  diameter. 

Let  us  now  consider  the  relative  merits  of  lead  and  iroa  as 
material  for  water-pipes  in  places  where  exposure  to  frost  is 
inevitable.  Lead  yields  more  than  iron,  and  so  far  has  an 
advantage  ;  this,  however,  is  but  limited.  As  lead  is  practi- 
cally inelastic,  every  stretch  remains,  and  every  stretch  di- 
minishes the  capacity  for  further  stretching  ;  the  lead  thus 
stretched  at  one  frost  is  less  able  to  stretch  again,  and  has 
lost  some  of  its  original  tenacity.  Hence  the  superiority  of 
new  leaden  pipes.  Iron  is  elastic  within  certain  limits,  and 
thus  the  iron  pipe  may  yield  a  little  without  permanent  strain 
or  "  distress,"  and  if  its  power  of  elastic  resistance  is  not 
exceeded,  it  regains  its  original  size  without  becoming  sensibly 
weaker.  Add  to  this  its  great  tenacity,  its  non-liability  to  be 
indented,  or  otherwise  to  vary  in  diameter,  and  we  have  a  far 
superior  material. 

But  this  conclusion  demands  some  qualification.  There  is 
iron  and  iron,  cast  iron  and  wrought  iron,  and  very  variable 
qualities  of  each  of  these.  I  need  scarcely  add  that  common 
brittle  cast  iron  is  quite  out  of  the  question  for  such  purposes, 
though  there  is  a  new  kind  of  cast  iron  or  semi-steel  coming 
forward  that  may  possibly  supersede  all  other  kinds  ;  but  this 
opens  too  wide  a  subject  for  discussion  in  the  present  paper, 
the  main  object  of  which  has  been  a  popular  exposition  of  the 
general  physical  laws  which  must,  be  obeyed  by  the  builder, 
or  engineer,  who  desires  to  construct  domestic  or  other  build- 
ings that  will  satisfy  the  wants  of  intelligent  people. 

The  mischievous  action  of  freezing  water  is  not  confined  to 
the  pipes  that  are  constructed  to  receive  or  convey  it.  Wher- 
ever water  may  be,  if  that  water  freezes,  it  must  expand  in  the 
degree  and  with  the  force  already  described.  If  it  penetrates 
stone  or  brick,  or  mortar  or  stucco,  and  freezes  therein,  one  of 
two  things  must  occur — either  the  superfluous  ice  must  exude 
at  the  surface  or  to  neighboring  cavities,  or  the  saturated 
material  must  give  way,  and  split  or  crumble  according  to  the 
manner  and  degree  of  penetration.  To  understand  this,  _the 
reader  must  remember  what  I  stated  about  the  little-understood 
viscosity  of  ice,  as  well  as  its  expansion  at  the  moment  of  freezing. 


34  SCIENCE   IX    SHORT   CHAPTERS. 

Bricks  arc  punished,  but  not  so  severely  as  might  be  antici- 
pated, seeing  how  porous  are  some  of  the  common  qualities, 
especially  those  used  in  London.  They  are  so  amply  porous 
that  the  water  not  only  finds  its  way  into  them  but  the  pores 
are  big  enough  and  many  enough  for  the  ice  to  demonstrate  its 
viscosity  by  squeezing  out  and  displaying  its  crystalline  struct- 
ure in  the  form  of  snow-like  efflorescence  on  the  surface.  This 
may  have  been  observed  by  some  of  my  readers  during  a 
severe  frost.  It  is  commonly  confounded  with  the  hoar-frost 
that  whitens  the  roofs  of  houses,  but  which  is  very  rarely  de- 
posited on  perpendicular  wall  faces. 

The  mortar  most  liable  to  suffer  is  that  which  is  porous  and 
pulverulent  within,  but  has  been  cleverly  faced  or  pointed  with 
a  crust  of  more  compact  material.  This  outer  film  prevents 
the  exuding  of  the  expanding  ice  crystals,  is  thrust  forth  bodily, 
and  retained  by  ice-cement  during  the  frost,  but  it  falls  in  scales 
when  this  temporary  binding  material  thaws.  Mortar  that  is 
compact  throughout  does  not  suffer  to  any  appreciable  extent. 
Tliis  is  proved  by  the  condition  of  the  remains  of  Roman  brick- 
work that  still  exist  in  Britain  and  other  parts  of  Europe. 
Some  of  the  old  shingle  walls  at  Brighton  and  other  parts  of 
the  south  coast,  where  the  chalk  for  lime -burning  was  at  the 
builder's  feet,  and  where  his  mortar  is  so  thickly  laid  between 
the  irregular  masses  of  flint,  also  show  the  possible  duration  of 
good  mortar.  The  jerry  builder's  mortar,  made  of  the  rid- 
dlings  of  burnt  clay  ballast  and  dust-hole  refuse  just  flavored 
with  lime,  crumbles  immediately,  because  these  materials  do 
not  combine  with  the  lime  as  fine  silicious  sand  gradually  does, 
to  form  an  impermeable  glassy  silicate. 

Stucco  is  punished  by  two  distinct  modes  of  action.  The 
first  is  where  the  surface  is  porous,  and  the  water  permeates 
accordingly  and  freezes.  This,  of  course,  produces  superficial 
crumbling,  which  should  not  occur  at  all  upon  good  material 
protected  by  suitable  paint.  The  other  case,  very  deplorable 
in  many  instances,  is  where  the  water  finds  a  space  between  the 
inner  surface  of  the  stucco  and  the  outer  surface  of  the  mate- 
rial upon  which  it  is  laid.  This  water,  when  frozen,  of  course, 
expands,  and  wedges  away  the  stucco  bodily,  causing  it  to 
come  down  in  masses  at  the  thaw.  This,  however,  only  occurs 
after  severe  frosts,  as  the  ordinary  mild  frosts  of  our  favored 
climate  seldom  endure  long  enough  to  penetrate  to  any  notable 
depth  of  so  bad  a  conductor  as  stone  or  stucco.  It  is  worthy  of 
note  that  water  is  a  still  worse  conductor  than  stone. 


THE   ACTION   OF   FROST   Itf    WATER-PIPES.  35 

Building  stones  are  so  various  both  in  chemical  composition 
and  mechanical  structure  that  the  action  of  freezing  water  is 
necessarily  as  varied  as  the  nature  of  the  material.  The  highly 
silicious  granites  (or,  rather,  porphyries  that  commonly  bear  the 
name  of  granite)  are  practically  impermeable  to  water  so  long 
as  they  are  free  from  any  chemical  decomposition  of  their 
f  eldspathic  constituents  ;  but  when  we  come  to  sandstones  and 
limestones,  or  intermediate  material,  very  wide  differences 
prevail. 

The  possible  width  of  this  difference  is  shown  in  the 
behavior  of  the  unselected  material  in  its  natural  home.  Cer- 
tain cliffs  and  mountains  have  stood  for  countless  ages  almost 
unchanged  by  the  action  of  frost  ;  others  are  breaking  up  with 
astonishing  rapidity  in  spite  of  apparent  solidity  of  structure. 
The  Matterhorn,  or  Mount  Cervin,  one  of  the  most  gigantic  of 
the  giant  Alps,  15,200  feet  high,  is  rendered  especial^ 
dangerous  to  ambitious  climbers  by  the  continual  crashing 
down  of  fragments  that  are  loosened  when  the  summer  sun 
melts  the  ice  that  first  separated  and  then  for  a  while  held  them 
in  their  original  places.  All  the  glaciers  of  the  Alps  are  more 
or  less  streaked  with  "  moraines/'  which  are  fragments  of  the 
mountains  that  freezing  water  has  detached. 

Our  stone  buildings  would  suffer  proportionally  if  some 
selection  of  material  were  not  made.  Generally  speaking,  this 
selection  is  based  upon  the  experience  of  previous  practical 
trials.  Certain  quarries  are  known  to  have  supplied  good 
material  of  a  certain  character,  and  this  quarry  has,  therefore, 
a  reputation  which  is  usually  of  no  small  value  to  its  fortunate 
owner.  Other  quarries  are  opened  in  the  neighborhood  wher- 
ever the  rock  resembles  that  of  the  tested  quarry. 

Sometimes,  however,  materials  are  open  for  selection  that 
have  not  been  so  well  tested,  and  a  method  of  testing  which  is 
more  expeditious  and  less  expensive  than  constructing  a  building 
and  watching  the  result,  is  very  desirable.  The  subject  of 
testing  building  materials  in  special  reference  to  their  resist- 
ance of  frost  was  brought  before  the  Academy  of  Science  of 
Paris  by  M.  Brard  some  years  since. 

In  his  preliminary  experiments  he  used  small  cubes  of  the 
stone  to  be  tested,  soaked  them  in  water,  and  then  exposed 
them  to  the  air  in  frosty  weather,  or  subjected  them  to  the 
action  of  freezing  mixtures.  Afterward  he  found  that  by  avail- 
ing himself  of  the  expansive  force  which  certain  saline  solutions 
exert  at  the  moment  of  crystallization,  he  could  conveniently 


36  SCIENCE   IN   SHORT   CHAPTERS. 

imitate  the  action  of  freezing  without  the  aid  of  natural  or 
artificial  frost.  Epsom  salts,  nitre,  alum,  sulphate  of  iron, 
Glauber's  salts,  etc.,  were  tried.  The  last-named,  Glauber's 
salt  (or  sulphate  of  soda),  which  is  very  cheap,  was  found 
to  be  the  best  for  the  purpose. 

His  method  of  applying  the  test  is  as  follows  :  Cut  the 
specimens  into  two-inch  cubes,  with  fiat  sides  and  sharp  edges 
and  corners,  mark  each  specimen  with  a  number,  either  by 
ink  or  scratching,  and  enter  in  a  book  all  particulars  concern- 
ing it.  Make  a  saturated  solution  of  the  sulphate  of  soda  in 
rain  or  distilled  water,  by  adding  the  salt  until  no  more  will 
dissolve  ;  perfect  saturation  being  shown  by  finding,  after 
repeated  stirring,  that  a  little  of  the  salt  remains  at  the  bottom 
an  hour  or  two  after  the  solution  was  made.  Heat  this  solu- 
tion in  a  suitable  vessel,  and  when  it  boils  put  in  the  marked 
specimens  one  by  one,  and  keep  them  immersed  in  the  boiling 
solution  for  half  an  hour.  Take  out  the  specimens  separately 
and  suspend  them  by  threads,  each  over  a  separate  vessel  con- 
taining some  of  the  liquid  in  which  they  were  boiled,  but 
which  has  been  carefully  strained  to  free  it  from  any  solid 
particles.  In  the  course  of  a  day  or  two,  as  the  cubes  dry, 
they  will  become  covered  with  an  efflorescence  of  snow-like 
crystals  ;  wash  these  away  by  simply  plunging  the  specimen 
into  the  vessel  below,  and  repeat  this  two  or  three  times  daily 
for  four  or  five  days  or  longer.  The  most  suitable  vessel  for 
the  purpose  is  a  glass  "  beaker,"  sold  by  venders  of  chemical 
apparatus. 

In  comparing  competing  samples,  be  careful  to  treat  all 
alike — i.e.  boil  them  together  in  the  same  solution,  and  dip 
them  an  equal  number  of  times  at  equal  intervals. 

Having  done  this,  the  result  is  now  to  be  examined.  If  the 
stone  is  completely  resistant  the  cube  will  remain  smooth  on 
its  surfaces  and  sharp  at  its  edges  and  corners,  and  there  will 
be  no  particles  at  the  bottom  of  the  vessel.  Otherwise,  the 
inability  of  the  stone  to  resist  the  test  will  be  shown  by  the 
disfigurement  of  the  cube  or  the  small  particles  wedged  off  and 
lying  at  the  bottom  of  the  liquid.  Care  must  be  taken  not  to 
confound  these  with  crystals  of  the  salt  which  may  also  be 
deposited.  These  crystals  are  easily  removed  by  adding  a 
little  more  water  or  warming  the  solution. 

For  strict  comparison  the  fragments  thus  separated  should  be 
weighed  in  a  delicate  balance,  such  as  is  used  in  chemical 
analysis. 


CHAPT2R  VI. 

FIRE-CLAY    AND    ANTHRACITE. 

FOR  household  fireplaces,  whether  open  or  closed,  these  may 
be  regarded  as  the  material  and  the  fuel  of  the  future,  and 
should  be  more  generally  and  better  understood  than  they  are. 

The  merits  of  fire-clay  were  fully  appreciated  and  described 
nearly  a  hundred  years  ago  by  that  very  remarkable  man, 
Benjamin  Thompson,  Count  of  Rumford.  Any  sound  scien- 
tific exposition  of  the  relative  value  of  fire-clay  and  iron  as  fire- 
place materials  can  be  little  more  or  less  than  a  repetition  of 
what  he  struggled  to  teach  at  the  beginning  of  the  present 
century. 

It  is  impossible  to  fairly  understand  this  subject  unless  we 
start  with  a  firm  grasp  of  first  principles.  The  business  before 
us  is  to  get  as  much  heat  as  possible  from  fuel  burning  in  * 
certain  fashion,  and  to  do  this  with  the  smallest  possible 
emission  of  smoke.  Substances  that  are  hotter  than  their 
surroundings  communicate  their  excess  of  temperature  in  three 
different  ways:  1st,  by  Conduction;  2d,  by  Convection; 
3d,  by  Radiation.  All  of  these  are  operating  in  every  form 
of  fireplace,  but  in  very  different  proportions  according  to 
certain  variations  of  construction. 

To  demonstrate  the  conduction  of  heat,  hold  one  end  of  a 
pin  between  the  finger  and  thumb,  and  the  other  end  in  the 
flame  of  a  candle.  The  experiment  will  terminate  very  speed- 
ily. Then  take  a  piece  of  a  lucifer  match  of  the  same  length 
as  the  pin,  and  hold  that  in  the  candle.  This  may  become 
red-hot  and  flaming  without  burning  the  fingers,  as  the  pin  did 
at  a  much  lower  temperature.  It  matters  not  whether  the  pin 
be  held  upward,  downward,  or  sideways,  the  heat  will  travel 
throughout  its  substance,  and  this  sort  of  travelling  is  called 
"conduction,"  and  the  pin  a  "conductor'1  of  heat.  The 
conducting  power  of  different  substances  varies  greatly,  as  the 
above  experiment  shows.  Metals  generally  are  the  best  con- 
ductors, but  they  differ  among  themselves  ;  silver  is  the  best 
of  all,  copper  the  next.  Calling  (for  comparison  sake)  the 
conductivity  of  silver  1000,  that  of  copper  is  736,  gold  532, 


38  SCIENCE   IN   SHORT   CHAPTERS. 

brass  236,  iron  119,  marble  and  other  building  stones  6  to  12, 
porcelain  5,  ordinary  brick  earth  only  4,  anid  fire-brick  earth 
less  than  this.  Thus  we  may  at  once  start  upon  our  subject, 
with  the  practical  fact  that  iron  conducts  heat  thirty  times 
more  readily  than  does  fire-brick. 

j  Convection  is  different  from  conduction,  inasmuch  as  it  is 
\  effected  by  the  movements  of  the  something  which  has  been 
heated  by  contact  with  something  else.  Water  is  a  very  bad 
conductor  of  heat,  much  worse  than  fire-brick,  and  yet,  as  we 
all  know,  heat  is  freely  transmitted  by  it,  as  when  we  boil  water 
in  a  kettle.  If,  however,  we  placed  the  water  in  a  fire-clay 
kettle,  and  applied  the  heat  at  the  top  we  should  have  to  wait 
for  our  tea  until  to-morrow  or  the  next  day.  When  the  heat  is 
applied  below,  the  hot  metal  of  the  kettle  heats  the  bottom  film 
of  water  by  direct  contact ;  this  film  expands,  and  thus,  being 
lighter,  rises  through  the  rest  of  the  water,  heating  other  por- 
tions by  contact  as  it  meets  them,  and  so  on  throughout. 
The  heat  is  thus  conveyed,  and  the  term  "  convection"  is 
based  on  the  view  that  each  particle  is  a  carrier  of  heat  as  it 
proceeds.  Air  conveys  heat  in  the  same  manner  ;  so  may  all 
gases  and  liquids,  but  no  such  convection  is  possible  in  solids. 
The  common  notion  that  "  heat  ascends  "  is  based  on  the 
well-known  facts  of  convection.  It  is  the  heated  gas  or  liquid 
that  really  ascends.  No  such  preference  is  given  to  an  upward 
direction,  when  heat  is  conducted  or  radiated. 

JKadiation  is  a  flinging  off  of  heat  in  all  directions  by  the 
heated  body.  Radiation  from  solids  is  mainly  superficial,  and 
it  depends  on  the  nature  of  the  heated  surface.  The  rougher 
and  the  more  porous  the  surface  of  a  given  substance  the 
better  it  radiates.  Bright  metals  are  the  worst  radiators  ; 
lampblack  the  best,  and  fire-brick  nearly  equal  to  it.  To  show 
the  effect  of  surface,  take  three  tin  canisters  of  equal  size,  one 
bright  outside,  the  second  scratched  and  roughened,  the  third 
painted  over  with  a  thin  coat  of  lampblack.  Fill  each  with  hot 
water  of  the  same  temperature,  and  leave  them  equally 
exposed.  Their  rates  of  radiation  will  then  be  measurable  by 
their  rates  of  cooling.  The  black  will  cool  the  most  rapidly, 
the  rough  canister  next,  and  the  bright  one  the  slowest. 

Radiant  heat  may  be  reflected  like  light  from  bright  surfaces, 
the  reflecting  substance  itself  becoming  heated  in  a  proportion 
which  diminishes  just  as  its  reflecting  powers  increase.  Good 
reflectors  are  bad  radiators  and  bad  absorbers  of  heat,  and  the 
power  of  absorbing  heat,  or  becoming  superficially  hot  when 


FIRE-CLAY   AND    ANTHRACITE.  39 

exposed  to  radiant  heat,  is  exactly  proportionate  to  radiating 
efficiency. 

Fire-clay  is  a  good  absorber  of  radiant  heat — i.e.  it  becomes 
readily  heated  when  near  to  hot  coals  or  flames,  without  requirs 
ing  actual  contact  with  them.  It  is  an  equally  good  radiator. 

"Let  us  now  apply  these  facts  to  fire-clay  in  fireplaces,  begin- 
ning with  ordinary*  open  grates  used  for  the  warming  of  apart- 
ments ;  first  supposing  that  we  have  an  ordinary  old-fashioned 
grate  all  made  of  iron — front,  sides,  and  back,  as  well  as  bars, 
and  next  that  we  have  another  of  similar  form  and  position, 
but  all  the  fire-box  and  the  back  and  cheeks  of  the  grate  made 
of  fire-clay. 

It  is  evident  that  the  fire-clay  not  in  actual  contact  with  the 
coals,  but  near  to  them,  will  absorb  more  heat  than  the  iron, 
and  thus  become  hotter.  Even  at  the  same  temperature  it  will 
radiate  much  more  heat  than  iron,  but  being  so  much  hotter 
this  advantage  will  be  proportionately  increased.  An  open 
fireplace  lined  throughout  with  fire-clay  thus  throws  into  the 
room  a  considerable  amount  of  its  own  radiation  in  addition  to 
that  thrown  out  from  the  coal. 

But  what  becomes  of  this  portion  of  the  heat  when  the  fire- 
place is  all  of  metal  ?  It  is  carried  up  the  chimney  by  con- 
vection, for  the  metal,  while  it  parts  with  less  heat  by  radia- 
tion, gives  up  more  to  the  air  by  direct  contact.  Therefore. 
if  we  must  burn  our  coals  inside  the  chimney,  we  lose  less  by 
burning  them  in  a  fire-clay  box  than  in  a  metal  box. 

Count  Rumford  demonstrates  this,  and  described  the  best 
form  of  open  firegrate  that  can  be  placed  in  an  ordinary  Eng- 
lish hole-in-the-wall  fireplace.  The  first  thing  to  be  done, 
according  to  his  instructions,  is  to  brick  up  your  large  square 
fireplace  recess,  so  that  the  back  of  it  shall  come  forward  to 
about  4  in.  from  the  front  inside  face  of  the  chimney,  thus 
contracting  the  throat  of  the  chimney,  just  behind  the  mantel, 
to  this  small  depth  (Rumford' s  device  for  sweeping  need  not 
be  here  described).  The  sides  or  "  covings"  of  this  shal- 
lowed recess  are  now  to  be  sloped  inward  so  that  each  one 
shall  horizontally  be  at  an  angle  of  135  degrees  to  the  plane 
of  this  new  back,  and  meet  it  at  a  distance  of  six  or  more  inches 
apart,  according  to  the  size  of  grate  required.  The  covings 
will  thus  spread  out  at  right  angles  with  each  other,  and  leave 
an  annular  opening  to  be  lined  with  fire-brick  and  run  straight 
up  to  the  chimney.  The  fire-bars  and  grate  bottom  to  be  sim- 
ply let  into  this  as  far  forward  as  possible. 


40  SCIENCE    IN   SHORT    CHAPTERS. 

By  this  simple  arrangement  we  get  a  firegrate  with  a  narrow 
flat  back  and  out-sloping  sides  ;  all  these  three  walls  are  of 
fire-brick  ;  the  back  radiates  perpendicularly  across  the  room  ; 
and  the  sloping  sides  radiate  outward,  instead  of  merely  across 
the  fire  from  one  to  the  other,  as  when  they  are  square  to  the 
walls. 

At  Rumford's  time  our  ordinary  fireplaces  were  square 
recesses  ;  now  we  have  adopted  something  like  his  suggestion 
in  the  sloping  sides  of  our  register  grates,  and  we  bring  our 
fireplaces  forward.  We  have  gone  backward  in  material,  by 
using  iron,  but  this,  after  all,  may  be  merely  due  to  the  iron- 
mongery interest  overpowering  that  of  the  bricklayers.  The 
preponderance  of  this  interest  in  the  South  Kensington  Exhibi- 
tion may  account  for  the  fact  that  Rumford's  simple  device 
was  not  to  be  seen  in  action  there.  It  could  not  pay  anybody 
to  exhibit  such  a  thing,  as  nobody  can  patent  it,  and  nobody 
can  sell  it.  I  have  seen  the  Rumford  arrangement  carried  out 
in  office  fireplaces  with  remarkable  success.  To  apply  it  any- 
where requires  only  an  intelligent  bricklayer,  a  few  bricks,  and 
some  iron  bars. 

Although  nobody  exhibited  this,  a  very  near  approach  to  it 
was  described  in  an  admirable  lecture  delivered  at  South  Ken- 
sington, by  Mr.  Fletcher,  of  Warrington.  In  one  respect  Mr. 
Fletcher  goes  further  than  Count  Rumford  in  the  application 
of  fire-clay.  He  makes  the  bottom  of  the  fire-box  of  a  slab  of 
fire-clay  instead  of  ordinary  iron  fire-bars.  This  demands  a 
little  more  trouble  and  care  in  lighting  the  fire,  owing  to  the 
absence  of  bottom-draught,  but  when  the  fire  is  well  started 
the  advantages  of  this  further  incasing  in  fire-clay  are  consider- 
able. They  depend  upon  another  effect  of  the  superior  radiant 
and  absorbent  properties  of  fire-clay  that  I  will  now  explain. 

So  far,  I  have  only  described  the  beneficial  effect  of  its  radia- 
tion on  the  room  to  be  heated,  but  it  performs  a  further  duty 
inside  the  fireplace  itself.  Being  a  bad  conductor,  it  does  not 
readily  carry  away  the  heat  of  the  burning  coal  that  rests  upon 
it,  and  being  also  an  excellent  absorber,  it  soon  becomes  very 
hot — i.e.  superficially  hot,  or  hot  where  its  heat  is  effective. 
This  action  may  be  seen  in  a  common  register  stove  with  fire- 
clay back  and  iron  sides.  When  the  fire  is  brisk  the  back  is 
visibly  red  hot,  while  the  sides  are  still  dull.  If,  after  such 
fire  has  burned  itself  out,  we  carefully  examine  the  ashes,  there 
will  be  found  more  fine  dust  in  contact  with  the  fire-brick  than 
with  the  iron — i.e.  evidence  of  more  complete  combustion 


FIRE-CLAY   AKD   ANTHRACITE.  41 

there  ;  and  one  of  the  advantages  justly  claimed  by  Mr.  Fletcher 
is,  that  with  his  solid  fire-clay  bottom  there  will  be  nounburned 
cinders — nothing  left  but  the  incombustible  mineral  ash  of  the 
coal.  Economy  and  abatement  of  smoke  are  the  necessary 
concomitants  of  such  complete  combustion. 

A  valuable  "  wrinkle"  was  communicated  by  Mr.  Fletcher. 
The  powdered  fire-clay  that  is  ordinarily  sold  is  not  easily 
applied  on  account  of  its  tendency  to  crumble  and  peel  off  the 
back  and  sides  of  the  stove  after  the  first  heating.  In  order 
to  overcome  this,  and  obtain  a  fine  compact  lining,  Mr. 
Fletcher  recommends  the  mixing  of  the  fire-clay  powder  with 
a  solution  of  water-glass  (silicate  of  soda)  instead  of  simple 
water.  It  acts  by  forming  a  small  quantity  of  glassy  silicate  of 
alumina,  which  binds  the  whole  of  the  clay  together  by  its  fu- 
sion when  heated. 

Londoners,  and,  in  fact,  Englishmen  generally,  have  hitherto 
regarded  anthracite  as  a  museum  mineral  and  a  curiosity,  rather 
than  an  every-day  coal-scuttle  commodity.  If  it  is  to  be  the 
fuel  of  the  future,  it  is  very  desirable  that  we  should  all  know 
something  about  its  merit  and  demerits,  as  well  as  the  possi- 
bilities of  supply. 

Anthracite  is  a  natural  coke.  From  its  position  in  the  earth, 
and  its  relations  to  bituminous  coal,  as  well  as  from  its  com- 
position, we  are  justified  in  regarding  it  as  a,  coal  that  was 
originally  bituminous,  but  which  has  been  altered  by  heat, 
acting  under  great  pressure.  In  the  great  coal-field  of  South 
Wales,  to  which  we  must  look  for  our  main  supply  of  anthra- 
cite, we  are  able  to  trace  the  action  of  heat  in  producing  a 
whole  series  of  different  classes  of  coal  in  a  single  seam,  which 
at  one  part  is  highly  bituminous — soft,  flaming  coal,  like  the 
Wallsend,  then  it  becomes  harder  and  less  bituminous,  then 
semi-bituminous  "  steam  coal,"  then  less  and  less  flaming 
until  at  last  we  have  the  hard  shiny  form  of  purely  carbona- 
ceous coal,  that  may  be  handled  without  soiling  the  fingers, 
and  which  burns  without  flame,  like  coke  or  charcoal.  This 
change  proceeds  as  the  seam  extends  from  the  east  toward  the 
west.  In  some  places  the  coal  at  the  base  of  a  hill  may  be 
anthracite,  while  that  on  the  outcrop  above  it  may  be  bitu- 
minous. 

An  artificial  anthracite  may  be  made  by  heating  coal  in  a 
closed  vessel  of  sufficient  strength  to  resist  the  expansion  of  the 
gases  that  are  formed.  It  differs  from  coke  in  being  com- 


4:2  SCIENCE   IN   SHORT   CHAPTERS. 

pact,  is  not  porous,  and  therefore,  of  course,  much  denser,  a 
given  weight  occupying  less  space. 

That  we  Englishmen  should  be  about  the  last  of  all  the 
coal-using  peoples  to  apply  anthracite  to  domestic  purposes  is  a 
very  curious  fact,  but  so  it  is.  In  America  it  is  the  ordinary 
fuel,  and  this  is  the  case  in  all  other  countries  where  it  is 
obtainable  at  the  price  of  bituminous  coal.  Our  perversity  in 
this  respect  shows  out  the  more  strikingly  when  we  go  a  little 
further  into  the  subject  by  comparing  the  two  classes  of  coal 
in  reference  to  our  methods  of  using  them,  and  when  we  con- 
sider the  fact  that  our  South  Wales  anthracite  is  far  superior 
to  the  American. 

Our  open  fires  only  do  their  small  fraction  of  useful  work  by 
radiation.  Their  convection  is  all  up  the  chimney.  Such 
being  the  case,  and  we  being  theoretically  regarded  as  rational 
beings,  it  might  be  supposed  that  for  our  national  and  espe- 
cially radiating  fireplaces  we  should  have  selected  a  coal  of 
especial  radiating  efficiency,  but,  instead  of  this,  we  do  the 
opposite.  The  flaming  coal  is  just  that  which  flings  the  most 
heat  up  the  chimney,  and  the  least  into  the  room,  and,  as 
though  we  were  all  struggling  to  destroy  as  speedily  as  possi- 
ble the  supposed  physical  basis  of  our  prosperity,  we  select 
that  coal  which  in  our  particular  fireplaces  burns  the  most 
wastefully.  If  we  had  closed  iron  stoves  with  long  stove- 
pipes in  the  room,  giving  to  the  air  the  heat  they  had  obtained 
by  the  convectivc  action  of  the  flame  and  smoke,  there  might 
be  some  reason  for  using  the  flaming  coal,  as  the  flame  would 
thereby  do  useful  work,  but,  as  it  is,  we  stubbornly  persist  in 
using  only  the  radiated  heat,  and  at  the  same  time  select  just 
the  coal  which  supplies  the  smallest  quantity  of  what  we 
require. 

No  scientific  dissertation  is  necessary  to  prove  the  superior 
radiating  power  of  an  anthracite  fire  to  anybody  who  has  ever 
stood  in  the  front  of  one.  This  is  most  strikingly  demonstrated 
by  those  grates  that  stand  well  forward,  and  are  kept  automat- 
ically filled  with  the  radiant-carbon. 

Let  us  now  see  ivhy  anthracite  is  a  better  radiator  than 
bituminous  coal.  This  is  due  to  its  chemical  composition. 
Of  all  the  substances  that  we  have  upon  the  earth  carbon  in  its 
ordinary  black  form  is  the  best  radiator.  Anthracite  contains 
from  90  to  94  per  cent,  of  pure  carbon,  bituminous  coal  from 
70  to  85,  and  much  of  this  being  combined  with  hydrogen 
burns  away  as  flame.  On  a  rough  average  we  may  say  that 


FIRE-CLAY   AND   ANTHRACITE.  43 

the  fixed  or  solid  carbon  capable  of  burning  with  a  smokeless, 
flameless  glow,  amounts  to  65  per  cent,  in  ordinary  British 
bituminous  coal,  against  an  average  of  92  per  cent,  in  British 
anthracite.  The  advantages  of  anthracite  as  a  fuel  for  opon 
radiating  grates  are  nearly  in  the  proportion  of  these  figures. 
Besides  this  it  contains  about  half  the  quantity  of  ash. 
Thus  we  see  that  from  a  purely  selfish  point  of  view,  and  quite 
irrespective  of  our  duty  to  our  fellow-citizens  as  regards  pol- 
luting the  atmosphere,  anthracite  is  preferable  to  ordinary  coal 
on  economical  grounds,  supposing  we  can  obtain  it  at  the  same 
price  as  bituminous  coal,  which  is  now  the  case. 

Another  great  advantage  of  anthracite  is  its  cleanliness.  It 
may  be  picked  up  in  the  fingers  without  soiling  them,  and  it  is 
similarly  cleanly  throughout  the  house.  It  produces  no 
"  blacks,"  no  grimy  dust,  and  if  it  were  generally  in  use 
throughout  London  one  half  of  the  house-cleaning  would  be 
saved.  White  curtains,  blinds,  etc.  might  hang  quite  four  times 
as  long,  and  then  come  down  not  half  so  dirty  as  now.  The 
saving  in  soap  alone,  without  counting  labor,  would  at  once 
return  a  handsome  percentage  on  the  capital  outlay  required 
for  reconstructing  all  our  fireplaces. 

Let  us  now  look  on  the  other  side,  and  ask  what  are  the 
disadvantages  of  anthracite,  and  why  is  it  not  at  once  adopted 
by  everybody  ?  There  is  really  only  one  disadvantage — viz. 
the  greater  difficulty  of  starting  an  anthracite  fire.  Practically 
this  is  considerable,  seeing  that  laziness  is  universal  and  ever 
ready  to  find  excuses  when  an  innovation  is  proposed  that 
stands  in  its  way.  To  light  an  anthracite  fire  in  an  ordinary 
fireplace  the  bellows  are  required  unless  a  specially  suitable 
draught  or  fire-lighter  is  used.  Some  recommend  that  an 
admixture  of  bituminous  coal  should  be  used  to  start  it,  but 
this  is  a  feeble  device  calculated  to  lead  to  total  failure,  seeing 
that  the  sole  originator  and  sustainer  of  our  ordinary  use  of 
bituminous  coal  is  domestic  ignorance  and  indolence,  and  if 
both  kinds  of  coal  are  kept  in  a  house  a  common  English 
servant  will  stubbornly  use  the  easy  lighting  kind,  and  solemnly 
assert  that  the  other  cannot  be  used  at  all.  The  only  way  to 
deal  with  this  obstacle,  the  human  impediment,  is  to  say, 
**  This  you  must  use,  or  go."  This  is  strictly  just,  as  a  simple 
enforcement  of  duty. 

At  the  same  time  some  help  should  be  supplied  in  the  way 
of  artificial  modes  of  creating  a  draught  in  starting  an  anthra- 
cite fire.  This  may  be  done  by  temporarily  closing  the  front 


44  SCIENCE   Ltf   SHORT   CHAPTERS. 

of  the  fire  by  a  "  blower,"  or  better  still  by  selecting  one  of 
the  grates  specially  devised  for  burning  anthracite,  of  which  so 
many  now  are  made.  Another  and  rather  important  matter  is 
to  obtain  the  anthracite  in  suitable  condition.  It  is  a  very  hard 
coal,  too  hard  to  be  broken  by  the  means  usually  at  hand  in 
ordinary  houses.  For  domestic  purposes  it  should  always  be 
delivered  broken  up  of  suitable  size,  from  that  of  an  egg  to  a 
cocoa-nut.  For  furnaces,  of  course,  large  lumps  are  preferable. 

Then,  again,  anthracite  must  not  be  stirred  and  poked 
about  ;  once  fairly  started  it  burns  steadily  and  brightly, 
demanding  only  a  steady  feeding.  The  best  of  the  special 
grates  are  more  or  less  automatic  in  the  matter  of  feeding,  and 
thus  the  trouble  of  lighting  is  fully  compensated  by  the 
absence  of  any  further  trouble. 

As  regards  the  supply.  This  for  London  and  the  greater 
part  of  England  will  doubtless  be  derived  from  the  great  coal- 
field of  South  Wales.  The  total  quantity  of  available  coal  in 
this  region,  after  deducting  the  waste  in  getting,  was  estimated 
by  the  Government  Commissioners  at  32,456  millions  of  tons. 
It  is  very  difficult  or  impossible  to  correctly  estimate  the  pro- 
portion of  anthracite  in  this,  but  supposing  it  to  be  one  tenth 
of  true  anthracite  it  gives  us  3245  millions  of  tons,  or  about 
enough  for  the  domestic  supply  of  the  whole  country  during 
100  years,  assuming  that  it  shall  be  used  less  wastefully  than 
we  are  now  using  bituminous  coal,  which  would  certainly  be  the 
case.  But,  including  the  imperfect  anthracite,  the  quantity 
must  be  far  larger  than  this,  and  we  have  to  add  the  other 
sources  of  anthracite. 

We  need  not,  therefore,  have  any  present  fear  of  insufficient 
supply  ;  probably  before  the  100  years  are  ended  we  shall  find 
other  souces  of  anthracite,  or  even  have  become  sufficiently 
civilized  to  abolish  altogether  our  present  dirty  devices,  and  to 
adopt  rational  methods  of  warming  and  ventilating  our  houses. 
When  we  do  this  any  sort  of  coal  may  be  used. 


CHAPTER  VII. 
COUNT  RUMFORD'S  COOKING-STOVES. 

IN  the  preceding  chapter  I  described  Count  Rumford's 
modification  of  the  English  open  firegrate  which  eighty  years 
ago  was  offered  to  the  British  nation  without  any  patent  or 
other  restrictions.  Its  non-adoption  I  believe  to  be  mainly  due 
to  this  —  it  was  nobody's  monopoly,  nobody's  business  to 
advertise  it,  and,  therefore,  nobody  took  any  fuither  notice  of 
it,;  especially  as  it  cannot  be  made  and  sold  as  a  separate  port- 
able article. 

An  ironmonger  or  stove-maker  who  should  go  to  the 
expense  of  exhibiting  Rumford's  simple  structure  of  tire-bricks 
and  a  few  bars  described  in  the  last  chapter,  would  be  super- 
seding himself  by  teaching  his  customers  how  they  may  advan- 
tageously do  without  him. 

The  same  remarks  apply  to  his  stoves  for  cooking  purposes. 
They  are  not  iron  boxes  like  our  modern  kitcheners,  but  are 
brick  structures,  matters  of  masonry  in  all  but  certain  adjuncts, 
such  as  bars,  fire-doors,  covers,  oven-boxes,  etc.,  which  are. 
very  simple  and  inexpensive.  Even  some  of  Rumford's  kitchen 
utensils,  such  as  the  steamers,  were  cheaply  covered  with 
•wood,  because  it  is  a  bad  conductor,  and  therefore  wastes  less 
hoat  than  an  iron  saucepan  lid. 

Rumford  was  no  mere  theorist,  although  he  contributed 
largely  to  pure  science.  His  greatest  scientific  discoveries 
were  made  in  the  course  of  his  persevering  efforts  to  solve 
practical  problems.  I  must  not  be  tempted  from  my  imme- 
diate subject  by  citing  any  examples  of  these,  but  may  tell  a 
fragment  of  the  story  of  his  work  so  far  as  it  bears  upon  the 
subject  of  cooking-ranges. 

He  began  life  as  a  poor  schoolmaster  in  New  Hampshire, 
when  it  was  a  British  colony.  He  next  became  a  soldier  ;  then 
a  diplomatist  ;  then  in  strange  adventurous  fashion  he  travelled 
on  the  Continent  of  Europe,  entered  the  Bavarian  service,  and 
began  his  searching  reform  of  the  Bavarian  army  by  improv- 
ing the  feeding  and  the  clothing  of  the  men.  He  became  a 
practical  working  cook,  in  order  that  they  should  be  supplied 
with  good,  nutritious,  and  cheap  food. 


46  SCIENCE   IN   SHORT    CHATTERS. 

But  this  was  not  all.  He  found  Munich  in  a  most  deplor- 
able condition  as  regards  mendicity  ;  and  took  in  hand  the 
gigantic  task  of  feeding,  clothing,  and  employing  the  over- 
whelming horde  of  paupers,  doing  this  so  effectually  that  he 
made  his  "  House  of  Industry"  a  true  workhouse  ;  it  paid  all 
its  own  expenses,  and  at  the  end  of  six  years  left  a  net  profit 
of  100,000  florins. 

I  mention  these  facts  in  confirmation  of  what  I  said  above 
concerning  his  practical  character.  Economical  cookery  was 
at  the  root  of  his  success  in  this  maintenance  of  a  workhouse 
without  any  poor-rates. 

After  doing  all  this  he  came  to  England,  visited  many  of  our 
public  institutions,  reconstructed  their  fireplaces,  and  then 
cooked  dinners  in  presence  of  distinguished  witnesses,  in 
order  to  show  how  lithe  need  be  expended  on  fuel,  when  it  is 
properly  used. 

At  the  Foundling  Institution  in  London  he  roasted  112  Ibs. 
of  beef  with  22  Ibs.  of  coal,  or  at  a  cost  of  less  than  threepence. 
The  following  copy  of  certificate,  signed  by  the  Councillor  of 
War,  etc.,  shows  what  he  did  at  Munich  :  "  We  whose 
names  are  underwritten  certify  that  we  have  been  present  fre- 
quently when  experiments  have  been  made  to  determine  the 
expense  of  fuel  in  cooking  for  the  poor  in  the  public  kitchen  of 
the  military  workhouse  at  Munich,  and  that  when  the  ordinary 
dinner  has  been  prepared  for  1000  persons,  the  expense  for 
fuel  has  not  amounted  to  quite  12  kreutzers. "  Twelve  kreut- 
zers  is  about  4%d.  of  our  money.  Thus,  only  -^  of  a  far- 
thing was  expended  on  cooking  each  person's  dinner,  although 
the  peas  which  formed  the  substantial  part  of  the  soup  required 
five  hours'  boiling.  The  whole  average  daily  fuel  expenses  of 
the  kitchen  of  the  establishment  amounted  to  ^  of  a  far- 
thing for  each  person,  using  wood,  which  is  much  dearer  than 
coal.  At  this  rate,  one  ton  of  wood  should  do  the  cooking  for 
ten  persons  during  two  years  and  six  days,  or  one  ton  of  coal 
would  supply  the  kitchen  of  such  a  family  three  and  a  half 
years. 

The  following  is  an  abstract  of  the  general  principles  which 
he  expounds  for  the  guidance  of  all  concerned  in  the  construc- 
tion of  cooking-stoves. 

1.  All  cooking  fires  should-be  inclosed. 

2.  Air  only  to  be  admitted  from  below  and  under  complete 
control.     All  air  beyond  what  is  required  for  the  supply  of 
oxygen  "  is  a  thief." 


COUNT   KUMFORD'S   COOKIXG-STOVES.  47 

3.  All  fireplaces  to  be  surrounded  by  non-conductors,  brick- 
work, not  iron. 

4.  The  residual  heat  from  the  fireplace  to  be  utilized  by  long 
journeys  in  returning  flues,  and  by  doing  the  hottest  work  .first. 

5.  Different  fires  should  be  used  for  different  work. 

The  first  of  these  requirements  encounters  one  of  our  dogged 
insular  prejudices.  The  slaves  to  these  firmly  believe  that 
meat  can  only  be  roasted  by  hanging  it  up  to  dry  in  front  of  an 
open  fire  ;  their  savage  ancestors  having  held  their  meat  on  a 
skewer  or  spit  over  or  before  an  open  fire,  modern  science  must 
not  dare  to  demonstrate  the  wasteful  folly  of  the  holy  sacrifice. 
Their  grandmothers  having  sent  joints  to  a  bakehouse,  where 
other  people  did  the  same,  and  having  found  that  by  thus 
cooking  beef,  mutton,  pork,  geese,  etc.,  some  fresh,  and  some 
stale,  in  the  same  oven,  the  flavors  became  somewhat  mixed, 
and  all  influenced  by  sage  and  onions,  these  people -persist  jn 
believing  that  meat  cannot  be  roasted  in  any  kind  of  closed 
chamber. 

Rumford  proved  the  contrary,  and  everybody  who  has 
fairly  tried  the  experiment  knows  that  a  properly  ventilated 
and  properly  heated  roasting  oven  produces  an  incomparably 
better  result  than  the  old  desiccating  process. 

Rumford' s  roaster  was  a  very  remarkable  contrivance, 
that  seems  to  have  been  forgotten.  It  probably  demands 
more  intelligence  in  using  it  than  is  obtainable  in  a  present-day 
kitchen.  When  the  School  Boards  have  supplied  a  better 
generation  of  domestic  servants  we  may  be  able  to  restore  its 
use. 

It  is  a  cylindrical  oven  with  a  double  door  to  prevent  loss  of 
heat.  In  this  the  meat  rests  on  a  grating  over  a  specially  con- 
structed gravy  and  water  dish.  Under  the  oven  are  two 
"  blow-pipes" — i.e.  stout  tubes  standing  just  above  the  fire  so 
as  to  be  made  red  hot,  and  opening  into  the  oven  at  the  back, 
and  above  the  fireplace  in  front,  where  there  is  a  plug  to  be 
closed  or  open  as  required.  Over  the  front  part  of  the  top  of 
the  oven  is  another  pipe  for  carrying  away  the  vapor.  It  is 
thus  used  :  The  meat  is  first  cooked  in  an  atmosphere  of 
steam  formed  by  the  boiling  of  water  placed  in  the  bottom  of 
the  double  dish,  over  which  the  meat  rests.  When  by  this 
means  the  meat  has  been  raised  throughout  its  whole  thickness 
to  the  temperature  at  which  its  albumen  coagulates,  the  plugs 
are  removed  from  the  blowpipes,  and  then  the  special  action  of 
roasting  commences  by  the  action  of  a  current  of  superheated 


48  SCIENCE   IN   SHORT   CHAPTERS. 

air  which  enters  below  and  at  the  back  of  the  oven,  travels 
along  and  finds  exit  above  and  in  front,  by  the  steam-pipe 
before  named. 

The  result  is  a  practical  attainment  of  theoretical  perfection. 
Instead  of  the  joint  being  dried  and  corticated  outside,  made 
tough,  leathery,  and  flavorless  to  about  an  inch  of  depth,  then 
fairly  cooked  an  inch  further,  and  finally  left  raw,  disgusting, 
and  bloody  in  the  middle,  as  it  is  in  the  orthodox  roasting  by 
British  cooks,  the  whole  is  uniformly  cooked  throughout  with- 
out the  soddeaing  action  of  mere  boiling  or  steaming,  as  the 
excess  of  moisture  is  removed  by  the  final  current  of  hot  dry 
air  thrown  in  by  the  blow-pipes,  which  at  the  same  time  give 
the  whole  surface  a  uniform  browning  that  can  be  regulated 
at  will  without  burning  any  portion  or  wasting  the  external  fat. 

Rumford's  second  rule,  that  air  be  admitted  only  from 
below,  and  be  limited  to  the  requirements,  is  so  simple  that  no 
comment  upon  it  is  needed.  Although  we  have  done  so  little 
in  the  improvement  of  domestic  fireplaces,  great  progress  has 
been  made  in  engine  furnaces,  blast  furnaces,  and  all  other  fire- 
places for  engineering  and  manufacturing  purposes.  Every 
furnace  engineer  now  fully  appreciates  Rumford's  assertion 
that  excess  of  cold  air  is  a  thief. 

The  third  rule  is  one  which,  as  I  have  already  stated,  stands 
seriously  in  the  way  of  any  commercial  "  pushing"  of  Rum- 
ford's  kitchen  ranges.  Those  which  he  figures  and  describes 
are  all  of  them  masonic  structures,  not  ironmongery  ;  the 
builder  must  erect  them,  they  cannot  be  bought  ready-made  ; 
but,  now  that  public  attention  is  roused,  I  believe  that  any 
builder  who  will  study  Rumford's  plans  and  drawings,  which 
are  very  practically  made,  may  do  good  service  to  himself  and 
his  customers  by  fitting  up  a  few  houses  with  true  Rumford 
kitcheners,  and  offering  to  reconstruct  existing  kitchen  ranges, 
especially  in  large  houses. 

The  fourth  rule  is  one  that  is  sorely  violated  in  the  majority 
of  kitcheners,  and  without  any  good  reason.  The  heat  from 
the  fire  of  any  kitchener,  whether  it  be  of  brick  or  iron, 
should  first  do  the  work  demanding  the  highest  temperature — 
viz.  roasting  and  baking,  then  proceed  to  the  boiler  or  boilers, 
and  after  this  be  used  for  supplying  the  bedrooms  and  bath- 
room and  the  housemaid,  etc.  with  hot  water  for  general  use, 
as  Rumford  did  in  his  house  at  Brompton  Row,  where  his 
chimney  terminated  in  metal  pipes  that  passed  through  a 
water-tank  at  the  top  of  the  house. 


COUNT  KUMFORD'S  COOKING-STOVES.  49 

Linen-closets  may  also  be  warmed  by  this  residual  heat. 

The  fifth  rule  is  also  violated  to  an  extent  that  renders  the 
words  uttered  by  Rumford  nearly  a  century  ago  as  applicable 
now  as  then.  He  said,  "  Nothing  is  so  ill-judged  as  most  of 
those  attempts  that  are  frequently  made  by  ignorant  projectors 
to  force  the  same  fire  to  perform  different  services  at  the  same 


Note  the  last  words,  ' '  same  time. ' '  In  the  uses  above 
mentioned  the  heat  does  different  work  successively,  which  is 
quite  different  from  the  common  practice  of  having  flues  to 
turn  the  flame  of  one  fire  in  opposite  directions,  to  split  its  heat 
and  make  one  fireplace  appear  to  do  the  work  of  two. 

Every  householder  knows  that  the  kitchen  fire,  whether  it 
be  an  old-fashioiied  open  fireplace,  or  a  modern  kitchener  of 
any  improved  construction,  is  a  very  costly  affair.  He  knows 
that  its  wasteful  work  produces  the  chief  item  of  his  coal  bill, 
but  somehow  or  other  he  is  helpless  under  its  infliction.  If  he 
has  given  any  special  attention  to  the  subject  he  has  probably 
tried  three  or  four  different  kinds  without  finding  any  notable 
relief.  Why  is  this  ?  I  venture  to  make  a  reply  that  will 
cover  90  per  cent,  or  probably  99  per  cent,  of  these  cases — viz. 
that  he  has  never  considered  the  main  source  of  waste,  which 
Rumford  so  clearly  defines  as  above,  and  which  was  eliminated 
in  all  the  kitchens  that  he  erected. 

Let  us  suppose  the  case  of  a  household  of  ten  persons,  but 
which  in  the  ordinary  course  of  English  hospitality  sometimes 
entertains  twice  that  number.  What  do  we  find  in  the  kitchen 
arrangements  ?  Simply  that  there  is  one  fireplace  suited  for  the 
maximum  requirements — i.e.  sufficient  for  twenty,  even  though 
that  number  may  not  be  entertained  more  than  half  a  dozen 
times  in  the  course  of  a  year.  To  cook  a  few  rashers  of 
bacon,  boil  a  few  eggs,  and  boil  a  kettle  of  water  for  break- 
fast, a  fire  sufficient  to  cook  for  a  dinner  party  of  twenty  is  at 
work.  This  is  kept  on  all  day  long,  because  it  is  just  possible 
that  the  master  of  the  house  may  require  a  glass  of  grog  at 
bedtime.  There  may  be  dampers  and  other  devices  for  regulat- 
ing this  fire,  but  such  regulation,  even  if  applied,  does  very 
little  so  long  as  the  capacity  of  the  grate  remains,  and  as  a 
matter  of  ordinary  fact  the  dampers  and  other  regulating 
devices  are  neglected  altogether  ;  the  kitchen  fire  is  blazing 
and  roaring  to  waste  from  6  or  7  A.M.  to  about  midnight,  in 
order  to  do  about  three  hours  and  a  half  work — i.e.  the  dinner 
for  ten,  and  a  nominal  trifle  for  the  other  meals. 


50  SCIENCE  Itf   SHORT   CHAPTERS. 

In  Rumford's  kitchens,  such  as  those  he  built  for  the  Baron 
de  Lerchenfeld  and  for  the  House  of  Industry  at  Munich,  the 
kitchener  is  a  solid  block  of  masonry  of  work-bench  hight  at 
top,  and  with  a  deep  bay  in  the  middle,  wherein  the  cook 
stands  surrounded  by  his  boilers,  steamers,  roasters,  ovens, 
etc.,  all  within  easy  reach,  each  one  supplied  by  its  own  sepa- 
rate fire  of  very  small  dimensions,  and  carefully  closed  with 
non-conducting  doors.  Each  fire  is  lighted  when  required, 
charged  with  only  the  quantity  of  fuel  necessary  for  the  work 
to  be  done,  and  then  extinguished  or  allowed  to  die  out. 

It  is  true  that  Rumford  used  wood,  which  is  more  easily 
managed  in  this  way  than  coal.  If  we  worked  as  he  did,  we 
might  use  wood  likewise,  and  in  spite  of  its  very  much  higher 
price  do  our  cooking  at  half  its  present  cost.  This  would 
effect  not  merely  "  smoke  abatement"  but  "smoke  extinc- 
tion, "  so  far  as  cooking  is  concerned.  But  the  lighting  of 
fires  is  no  longer  a  troublesome  and  costly  process  as  in  the 
days  of  halfpenny  bundles  of  firewood.  To  say  nothing  of 
the  improved  fire-lighters,  we  have  gas  everywhere,  and  noth- 
ing is  easier  than  to  fix  or  place  a  suitable  Bunsen  or  solid 
flame  burner  under  each  of  the  fireplaces  (an  iron  gaspipc, 
perforated  below  to  avoid  clogging,  will  do),  and  in  two  or 
three  minutes  the  coals  are  in  full  blaze  ;  then  the  gas  may  be 
turned  off.  The  writer  has  used  such  an  arrangement  in  his 
study  for  some  years  past,  and  starts  his  fire  in  full  blaze  in 
three  minutes  quite  independent  of  all  female  interference. 

I  have  no  doubt  that  ultimately  gas  will  altogether  supersede 
coal  for  cooking  ;  but  this  and  all  other  scientific  improvements 
in  domestic  comfort  and  economy  must  be  impossible  with  the 
present  generation  of  uneducated  domestics,  whose  brains 
(with  few  exceptions)  have  become  torpid  and  wooden  from 
lack  of  systematic  exercise  during  their  period  of  growth. 


CHAPTER  VIII. 

THE    "  CONSUMPTION    OF    SMOKE.*' 

A  GREAT  deal  has  been  spoken  and  written  of  this  subject,  but 
practically  nothing  has  been  done.  At  one  time  I  shared  the 
general  belief  in  its  possibility,  and  accordingly  examined  a 
multitude  of  devices  for  smoke-consuming,  and  tried  several  of 
the  most  promising,  chiefly  in  furnaces  for  metallurgical  work, 
for  steam  boilers  and  stills.  None  of  them  proved  satisfactory, 
and  I  was  driven  to  the  conclusion  that  smoke-consumption  is  a 
delusion,  and  further,  that  economical  consumption  of  smoke  is 
practically  impossible.  When  smoke  is  once  formed,  the  cost 
of  burning  it  far  exceeds  the  value  of  the  heat  that  is  produced 
by  the  combustion  of  its  very  flimsy  flocculi  of  carbon.  It  is 
a  fiend  that  once  raised  cannot  be  exorcised,  a  Frankenstein 
that  haunts  its  maker,  and  will  not  be  appeased. 

To  describe  in  detail  the  many  ingenious  devices  that  have 
been  proposed  and  expensively  patented  and  advertised  for  this 
object  would  carry  me  far  beyond  the  intended  limits  of  this  pa- 
per. I  must  not  even  attempt  this  for  a  selected  few,  as  even 
among  them  th»?re  is  none  that  can  be  pronounced  satisfactory. 

The  common  idea  is  that  if  the  smoke  be  carried  back  to  the 
fire  that  produced  it,  and  made  to  pass  through  it  again,  a 
recombustion  or  consumption  of  the  smoke  will  take  place. 
This  is  a  mistake,  as  a  little  reflection  will  show.  First,  let  us 
ask  why  did  this  particular  fire  produce  such  smoke  ?  Every- 
body nowadays  can  answer  this  question,  as  we  all  know  that 
smoke  is  a  result  of  imperfect  combustion,  and,  knowing  this, 
it  can  easily  be  understood  that  to  return  the  carbonic  acid  and 
excess  of  carbon  to  the  already  suffocated  fire  can  only  add 
smother  to  smotheration,  and  make  the  smoky  fire  more  smoky 
still. 

There  is,  however,  one  case  in  which  a  fire  appears  to  thus 
consume  its  own  smoke,  but  the  appearance  is  delusive.  I 
refer  to  fires  lighted  from  above.  These,  if  properly  managed, 
are  practically  smokeless,  and  it  is  commonly  supposed  that 
smoke  passes  from  the  raw  coal  below  through  the. burning 
coal  above,  and  is  thereby  consumed.  The  fact  is,  however, 
that  no  such  smoke  is  formed.  That  which  under  these  condi- 
tions comes  from  the  coal  beneath,  when  gradually  heated  by 


53  SCIENCE   IN    SHORT   CHAPTERS. 

the  fire  above,  is  combustible  gas,  and  this  gas  is  burned  as  it 
passes  through  the  fire.  In  this  case  the  formation  or  non- 
formation  of  smoke  depends  mainly  on  how  this  gas  is  burned, 
whether  completely  or  incompletely.  If  the  air  supplied  for 
its  combustion  is  insufficient,  smoke  will  be  formed  as  it  is 
when  we  turn  up  an  Argand  gas-flame  so  high  that  the  gas  is 
too  great  in  proportion  to  the  quantity  of  air  that  can  enter  the 
glass  chimney. 

Herein  lies  the  fundamental  principle.  We  may  prevent 
smoke,  though  we  cannot  cure  it,  and  this  prevention  depends 
upon  how  we  supply  air  to  the  gas  which  the  coal  gives  off 
when  heated,  and  upon  the  condition  of  this  gas  when  we 
bring  it  in  contact  with  the  air  by  which  its  combustion  is  to 
be  effected.  We  must  always  remember  that  coal  when  its 
temperature  is  sufficiently  heated,  whether  in  a  gas  retort  or 
fireplace,  gives  off  a  series  of  combustible  hydrocarbon  gases 
and  vapors,  and  all  we  have  to  do  in  order  to  obtain  smokeless 
fires  is  to  secure  the  complete  combustion  of  these. 

Now  we  know  that  to  burn  a  given  quantity  of  gas  we  must 
supply  it  with  a  sufficient  quantity  of  oxygen — i.e.  of  the  active 
principle  of  the  air  ;  but  this  is  not  all  ;  we  all  know  well 
enough  that  if  cold  coal  gas  and  cold  air  be  brought  together 
in  any  proportion  whatever  no  combustion  occurs.  A  certain 
amount  of  heat  is  necessary  to  start  the  chemical  combination 
of  oxygen  with  hydrogen  and  carbon,  which  combination  is 
the  combustion,  or  burning. 

Therefore,  when  the  coal  gas  and  the  air  are  brought 
together,  one  or  the  other,  or  both,  must  be  heated  up  to  a 
certain  point  in  order  that  the  combustion  be  complete.  If 
cold,  there  is  no  combustion  ;  if  insufficiently  heated,  there  is 
imperfect  combustion,  however  well  the  supplies  may  be 
regulated. 

A  very  simple  experiment  that  anybody  may  make  illustrates 
this.  When  an  ordinary  open  fire  is  burning  brightly  and 
clearly  without  flame,  throw  a  few  small  pieces  of  raw  coa 
into  the  midst  of  the  glowing  coals.  They  will  flame  fiercely, 
but  without  smoking.  Then  throw  a  heap  of  coal  or  one  large 
lump  on  a  similar  fire.  Now  you  will  have  dense  volumes  of 
smoke,  and  little  or  no  flame,  simply  because  the  cooling 
action  of  the  large  bulk  of  coal  in  the  course  of  distillation 
brings  the  temperature  of  its  gases  below  that  required  for 
their  complete  combustion. 

This  simple  experiment  supplies  a  most  important  p; apical 


lesson,  as  well  as  a  philosophical  example.  The  best  of  all 
smoke-abatement  machines  is  an  intelligent  and  conscientious 
stoker,  and  every  contrivance  for  smoke  abatement  must,  in 
order  to  be  efficient,  either  be  fed  by  such  a  stoker  or  provided 
•with  some  automatic  arrangement  by  which  the  apparatus  itself 
does  the  work  of  such  a  stoker  by  supplying  the  fresh  fuel 
just  when  and  where  it  is  wanted. 

Cornish  experience  is  very  instructive  in  his  respect.  The 
engines  that  pump  the  water  from  the  mines  do  a  definitely 
measureable  amount  of  work,  and  are  made  to  register  this. 
The  stoker  is  a  skilled  workman,  and  prizes  are  given  to  those 
who  obtain  the  largest  amount  of  "  duty"  from  given  engines 
per  ton  of  coal  consumed.  Instead  of  pitching  his  coal  in  any- 
how, cramming  his  firehole,  and  then  sitting  down  to  sleep  or 
smoke  in  company  with  his  chimney,  the  Cornish,  or  other 
good  fireman,  feeds  little  and  often,  and  deftly  sprinkles  the 
contents  of  his  shovel  just  where  the  fire  is  the  brightest  and 
the  hottest,  and  the  bars  are  the  least  thickly  covered.  The 
result  is  remarkable.  A  colliery  proprietor  of  South  Stafford- 
shire was  visiting  Cornwall,  and  went  with  a  friend  to  see  his 
works.  On  approaching  the  engine-house  and  seeing  a  white- 
washed shaft  with  no  smoke  issuing  from  its  mouth,  he 
.expressed  his  disappointment  at  finding  that  the  engine  was 
not  at  work.  To  all  who  have  been  accustomed  to  the  "  Black 
Country,"  where  coal  is  so  shamefully  wasted  because  it  is 
cheap,  the  tall  clean  whitewashed  shafts  of  Cornwall,  all  so 
smokebss,  present  quite  an  astonishing  appearance. 

This  is  not  a  result  of  "  smoke-consuming"  apparatus,  but 
mainly  of  careful  firing.  It  was  in  the  first  place  promoted  by 
the  high  price  of  coal  due  to  the  cost  of  carriage  before  the 
Cornish  railways  were  constructed,  and  it  brought  about  a 
curious  result.  Horse-power  for  horse-power,  the  cost  of  fuel 
for  working  Cornish  pumping  engines  has  been  brought  below 
that  of  pumping  engines  in  the  places  where  the  price  of  coal 
per  ton  was  less  than  one  half.  Another  coal  famine,  that 
should  raise  the 'price  of  coal  in  London  to  60s.  per  ton,  and 
keep  it  there  for  two  or  three  years,  would  effect  more  smoke 
abatement  than  we  can  hope  to  result  from  the  present  and 
many  future  South  Kensington  efforts.  I  need  scarcely  dwell 
upon  the  necessity  for  a  due  supply  of  air.  This  is  well  under- 
s!o)d  by  everybody.  An  over-supply  of  air  does  mischief,  by 
carrying  away  wastefully  a  proportionate  quantity  of  heat. 
The  waste  due  to  this  is  sometimes  very  serious. 


f>l  SCIENCE   IX   SHORT    CHAPTERS. 

After  reviewing  all  that  has  been  done,  the  conclusion  that 
London  cannot  become  a  clean,  smokeless,  and  beautiful  city, 
so  long  as  we  are  dependent  upon  open  firegrates  of  anything 
like  ordinary  construction,  and  fed  with  bituminous  coal,  is 
inevitable.  The  general  use  of  anthracite  would  effect  the 
desired  change,  but  there  is  no  hope  of  its  becoming  general 
without  legislative  compulsion,  and  Englishmen  will  not  submit 
to  this. 

One  of  the  most  hopeful  schemes  is  that  which  was  pro- 
pounded a  short  time  since  by  Mr.  Scott  Moncrieff.  In- 
stead of  receiving  our  coal  in  its  crude  state,  he  proposes  that 
we  should  have  its  smoke  -  producing  constituents  removed 
before  it  is  delivered  to  us  ;  that  it  should  be  made  into  a  sort 
of  artificial  semi-anthracite  at  the  gas-works  by  a  process  of 
half  distillation,  which  would  take  away  not  all  the  flaming  gas 
as  at  present,  but  that  portion  which  is  by  far  the  richest  to 
the  gas-maker  and  the  most  unmanageable  in  common  fires. 
We  should  thus  have  a  material  which,  instead  of  being  so 
difficult  to  light  as  coke  and  anthracite,  would  light  more 
easily  than  crude  coal,  and  at  the  same  time  our  gas  would  have 
far  greater  illuminating  power,  as  it  would  all  be  drawn  off 
during  the  early  period  of  distillation,  when  it  is  at  its  richest. 
From  a  given  quality  of  coal  the  difference  would  be  as  twenty- 
four  candles  to  sixteen.  The  ammonia  which  we  now  throw 
into  the  air,  the  naphtha  and  coal-tar  products  which  we  waste, 
are  so  valuable  that  they  would  pay  all  the  expenses  at  the  gas- 
works and  leave  a  handsome  profit.  We  should  thus  get  gas 
so  much  better  that  two  burners  would  do  the  work  now 
obtained  from  three.  We  should  get  all  we  require  for  light- 
ing purposes  and  plenty  more  for  heating  ;  the  intermediate 
profits  of  the  coal  merchant  would  be  abolished,  and  our  solid 
fuel  of  far  better  quality  could  be  supplied  twenty  or  thirty  per 
cent,  cheaper  than  at  present,  provided  always  that  the  gas 
monopoly  were  abolished,  "  a  consummation  most  devoutly  to 
be  wished  for. ' ' 

Mr.  Moncrieff  (who  brought  forward  his  scheme  without 
any  company-mongering,  or  claims  for  patent  rights)  estimates 
the  saving  to  London  at  £2,125,000  per  annum,  over  and 
above  the  far  greater  saving  that  would  result  from  the  aboli- 
tion of  smoke. 

In  connection  with  this  scheme  I  may  mention  a  fact  that 
has  not  been  hitherto  noted — viz.  that  we  have  perforce  and 
unconsciously  done  a  little  in  this  direction  already.  Formerly 


THE   AIR   OF   STOVE-HEATED    ROOMS.  55 

London  was  supplied  almost  exclusively  with  "  Wallsend  "  and 
other  sea-borne  coals  of  a  highly  bituminous  composition — soft 
coals  that  fused  in  the  grate  and  caked  together.  Partly  owing 
to  exhaustion  of  the  seams,  and  partly  to  the  competition  of 
railway  transit,  we  now  obtain  a  large  proportion  of  hard  coal 
from  the  Midlands.  This  is  less  smoky  and  less  sooty,  and 
hence  the  Metropolitan  smoke  nuisance  has  not  increased  quite 
as  greatly  as  the  population. 

But  I  will  now  conclude  by  repeating  that  whatever  scheme 
be  chosen,  "smoke  abatement"  is  to  be  achieved,  not  by 
smoke-consumption,  but  by  smoke-prevention* 


CHAPTER   IX. 

THE    AIR    OF    STOVE- HEATED    ROOMS. 

WHATEVER  opinions  may  be  formed  of  the  merits  of  the 
exhibits  at  South  Kensington,  one  result  is  unquestionable — the 
exhibition  itself  has  done  much  in  directing  public  attention 
to  the  very  important  subject  of  economizing  fuel  and  the 
diminution  of  smoke.  We  sorely  need  some  lessons.  Our 
national  progress  in  this  direction  has  been  simply  contempti- 
ble, so  far  as  domestic  fireplaces  are  concerned. 

To  prove  this  we  need  only  turn  back  to  the  essays  of  Ben- 
jamin Thompson,  Count  of  Rumford,  published  in  London 
just  eighty  years  ago,  and  find  therein  nearly  all  that  the 
Smoke  Abatement  Exhibition  ought  to  teach  us,  both  in  theory 
and  practice — lessons  which  all  our  progress  since  1802,  plus 
the  best  exhibits  at  South  Kensington,  we  have  yet  to  learn. 

This  small  progress  in  domestic  heating  is  the  more  remark- 
able when  contrasted  with  the  great  strides  we  have  made  in 
the  construction  and  working  of  engineering  and  metallurgical 
furnaces,  the  most  important  of  which  is  displayed  in  the 
Siemens  regenerative  furnace.  A  climax  to  this  contrast  is 
afforded  by  a  speech  made  by  Dr.  Siemens  himself,  in  which  he 
defends  our  domestic  barbarisms  with  all  the  conservative 
inconvincibility  of  a  born  and  bred  Englishman,  in  spite  of  his 
German  nationality. 

The  speech  to  which  I  refer  is  reported  in  the  Journal  of 


5G  SCIENCE   IN    SHORT   CHAPTERS. 

the  Society  of  Arts,  December  9th,  1881,  and  contains  some 
curious  fallacies,  probably  due  to  its  extemporaneous  character  ; 
but  as  they  have  been  quoted  and  adopted  not  only  in  political 
and  literary  journals,  but  also  by  a  magazine  of  such  high 
scientific  standing  as  Nature  (see  editorial  article,  January 
5th,  1882,  p.  219),  they  are  likely  to  mislead  many. 

Having  already,  in  my  "  History  of  Modern  Invention, 
etc.,"  and  in  other  places,  expressed  my  great  respect  for  Dr. 
Siemens  and  his  benefactions  to  British  industry,  the  spirit  in 
which  the  following  plain-spoken  criticism  is  made  will  not,  I 
hope,  be  misunderstood  either  by  the  readers  of  Knowledge  or 
by  Dr.  Siemens  himself. 

I  may  further  add  that  I  am  animated  by  a  deadly  hatred  of 
our  barbarous  practice  of  wasting  precious  coal  by  burning  it 
in  iron  fire-baskets  half  buried  in  holes  within  brick  walls,  and 
under  shafts  that  carry  80  or  90  per  cent,  of  its  heat  to  the 
clouds  ;  that  pollute  the  atmosphere  of  our  towns,  and  make 
all  their  architecture  hideous  ;  that  render  scientific  and  effi- 
cient ventilation  of  our  houses  impossible  ;  that  promote  rheuma- 
tism, neuralgia,  chilblains,  pulmonary  diseases,  bronchitis,  and 
all  the  other  "  ills  that  flesh  is  heir  to"  when  roasted  on  one 
side  and  cold-blasted  on  the  other  ;  that  I  am  so  rabid  on  this 
subject,  that  if  Dr.  Siemens,  Sir  F.  Bramwell,  and  all  others 
who  defend  this  English  abomination,  were  giant  windmills  in 
full  rotation,  I  would  emulate  the  valor  of  my  chivalric  pred- 
ecessor, whatever  might  be  the  personal  consequences. 

Dr.  Siemens  stated  that  the  open  fireplace  "  communicates 
absolutely  no  heat  to  the  air  of  the  room,  because  air,  being  a 
perfectly  transparent  medium,  the  rays  of  heat  pass  clean 
through  it." 

Here  is  an  initial  mistake.  It  is  true  that  air  which  has 
been  artificially  deprived  of  all  its  aqueous  vapor  is  thus  com- 
pletely permeable  by  heat  rays,  but  such  is  far  from  being  the 
case  with  the  water  it  contains.  This  absorbs  a  notable  amount 
even  of  bright  solar  rays,  and  a  far  greater  proportion  of  the 
heat  rays  from  a  comparatively  obscure  source,  such  as  the  red- 
hot  coals  and  flame  of  a  common  fire.  Tyndall  has  proved  that 
8  to  10  per  cent,  of  all  the  heat  radiating  from  such  a  source  as 
a  common  fire  is  absorbed  in  passing  through  only  5  feet  of  air 
in  its  ordinary  condition,  the  variation  depending  upon  its 
degree  of  saturation  with  aqueous  vapor. 

Starting  with  the  erroneous  assumption  that  the  rays  of  heat 
pass  "  clean  through"  the  air  of  the  room,  Dr.  Siemens  went 


THE   AIR   OF   STOVE-HEATED   KOOMS.  57 

on  to  say  that  the  open  fireplace  "  gives  heat  only  by  heating 
the  walls,  ceiling,  and  furniture  ;  and  here  is  the  great  advan- 
tage of  the  open  fire  ;"  and,  further,  that  "  if  the  air  in  the 
room  were  hotter  than  the  walls,  condensation  would  take 
place  on  them,  and  mildew  and  fermentation  of  various  kinds 
would  be  engendered  ;  whereas,  if  the  air  were  cooler  than  the 
walls,  the  latter  must  be  absolutely  dry." 

Upon  these  assumptions,  Dr.  Siemens  condemns  steam 
pipes  and  stoves,  hot-air  pipes,  and  all  other  methods  of 
directly  heating  the  air  of  apartments,  and  thereby  making  it 
warmer  than  were  the  walls-,  the  ceiling,  and  furniture  when 
the  process  of  warming  commenced.  It  is  quite  true  that 
stoves,  stove-pipes,  hot-air  pipes,  steam  pipes,  etc.  do  this  : 
they  raise  the  temperature  of  the  air  directly  by  convection — 
i.e.  by  warming  the  film  of  air  in  contact  with  their  surfaces, 
which  film,  thus  heated  and  expanded,  rises  toward  the  ceil- 
ing, and,  on  its  way.  warms  the  air  around  it,  and  then  is 
followed  by  other  similarly  heated  ascending  films.  When  we 
make  a  hole  in  the  wall,  and  burn  our  coals  within  such  cavity, 
this  convection  proceeds  up  the  chimney  in  company  with  the 
smoke. 

But  is  Dr.  Siemens  right  in  saying  that  the  air  of  a  room, 
raised  by  convection  above  its  original  temperature,  and  above 
that  of  the  walls,  deposits  any  of  its  moisture  on  these  walls  ? 
I  have  no  hesitation  in  saying  very  positively  that  he  is  clearly 
and  demonstrably  wrong  ;  that  no  such  condensation  can  possi- 
bly take  place  under  the  circumstances. 

Suppose,  for  illustration  sake,  that  we  start  with  a  room  of 
which  the  air  and  walls  are  at  the  freezing  point,  32°  Fain1., 
before  artificial  heating  (any  other  temperature  will  do),  and, 
to  give  Dr.  Siemens  every  advantage,  we  will  further  suppose 
that  the  air  is  fully  saturated  with  aqueous  vapor — i.e.  just  in 
the  condition  at  which  some  of  its  water  might  be  condensed. 
Such  condensation,  however,  can  only  take  place  by  cooling 
the  air  below  32°,  and  unless  the  walls  or  ceiling  or  furniture 
are  capable  of  doing  this  they  cannot  receive  any  moisture  due 
to  such  condensation,  or,  in  other  words,  they  must  fall  below 
32°  in  order  to  obtain  it  by  cooling  the  film  in  contact  with 
them.  Of  course  Dr.  Siemens  will  not  assert  that  the  stoves 
or  steam-pipes  (inclosing  the  steam,  of  course),  or  the  hot-air 
or  hot-water  pipes,  will  lower  the  absolute  temperature  of  the 
walls  by  heating  the  air  in  the  room. 

But  if  the  air  is  heated  more  rapidly  than  are  the  walls,  etc. 


58  SCIENCE   IN   SHOUT   CHAPTEKS. 

the  relative  temperature  of  these  will  be  lower.  Will  conden- 
sation of  moisture  then  follow,  as  Dr.  Siemens  affirms  ?  Let  us 
suppose  that  the  air  of  the  room  is  raised  from  30°  to  50°  by 
convection  purely  ;  reference  to  tables  based  on  the  researches 
of  Regnault  shows  that  at  32°  the  quantity  of  vapor  required 
to  saturate  the  air  is  sufficient  to  support  a  column  of  0-182 
inch  of  mercury,  while  at  50°  it  amounts  to  0'361,  or  nearly 
double.  Thus  the  air,  instead  of  being  in  a  condition  of  giving 
away  its  moisture  to  the  walls,  has  become  thirsty,  or  in  a  con- 
dition to  take  moisture  away  from  them  if  they  are  at  all  damp. 
This  is  the  case  whether  the  walls  remain  at  32°  or  are  raised 
to  any  higher  temperature  short  of  that  of  the  air. 

Thus  the  action  of  close  stoves  and  of  hot  surfaces  or  pipes 
of  any  kind  is  exactly  the  opposite  of  that  attributed  to  them 
by  Dr.  Siemens.  They  dry  the  air,  they  dry  the  walls,  they 
dry  the  ceiling,  they  dry  the  furniture  and  everything  else  in 
the  house. 

In  our  climate,  especially  in  the  infamous  jerry-built  houses 
of  suburban  London,  this  is  a  great  advantage.  Dr.  Siemens 
states  his  American  experience,  and  denounces  such  heating  by 
convection  because  the  close  stoves  there  made  him  uncomfort- 
able. This  was  due  to  the  fact  that  the  winter  atmosphere 
of  the  United  States  is  very  dry,  even  when  at  zero.  But 
air,  when  raised  from  0°  to  60°,  acquires  about  twelve  times 
its  original  capacity  for  water.  The  air  thus  simply  heated  is 
desiccated,  and  it  desiccates  everything  in  contact  with  it, 
especially  the  human  body.  The  lank  and  shrivelled  aspect  of 
the  typical  Yankee  is,  I  believe,  due  to  this.  He  is  a  desic- 
cated Englishman,  and  we  should  all  grow  like  him  if  our 
climate  were  as  dry  as  his.*  The  great  fires  that  devastate 
the  cities  of  the  United  States  appear  to  me  to  be  due  to  this 
general  desiccation  of  all  building  materials,  rendering  them 
readily  inflammable  and  the  flames  difficult  of  extinction. 

When  an  undesiccated  Englishman,  or  a  German  endowed 
with  a  wholesome  John  Bull  rotundity,  is  exposed  to  this 
superdried  air,  he  is  subjected  to  an  amount  of  bodily  evapora- 
tion that  must  be  perceptible  and  unpleasant.  The  disagreeable 
sensations  experienced  by  Dr.  Siemens  in  the  stove-heated 
railway  cars,  etc.  were  probably  due  to  this. 

*  In  each  of  my  three  visits  to  America  I  lost  about  thirty  pounds 
in  weight,  which  I  recovered  within  a  few  months  of  my  return  to 
the  "home  country"  (of  English  speaking  nations). — EICHAKD  A. 
PEOCTOE. 


THE   AIR   OF   STOVE-HEATED   ROOMS.  59 

An  English  house,  enveloped  in  a  foggy  atmosphere,  and 
incased  in  damp  surroundings,  especially  requires  stove- heating 
and  the  most  inveterate  worshippers  of  our  national  domestic 
fetich,  the  open  grate,  invariably  prefer  a  stove  or  hot-pipe- 
heated  room,  when  they  are  unconscious  of  the  source  of  heat, 
and  their  prejudice  hoodwinked.  I  have  observed  this  con- 
tinually, and  have  often  been  amused  at  the  inconsistency  thus 
displayed.  For  example,  one  evening  I  had  a  warm  contest 
with  a  lady,  who  repeated  the  usual  praises  of  the  cheerful 
blaze,  etc.,  etc.  On  calling  afterward,  on  a  bitter  snowy 
morning,  I  found  her  and  her  daughters  sitting  at  work  in  the 
billiard-room,  and  asked  them  why.  "  Because  it  is  so  warm 
and  comfortable."  This  room  was  heated  by  an  8-inch  steam- 
pipe,  running  around  and  under  the  table,  to  prevent  the 
undue  cooling  of  the  india-rubber  cushions,  and  thus  the  room 
was  warmed  from  the  middle,  and  equally  and  moderately 
throughout.  The  large  reception-room,  with  blazing  fire,  was 
scorching  on  one  side  and  freezing  on  the  other,  at  that  time 
in  the  morning. 

The  permeability  of  ill-constructed  iron  stoves  to  poisonous 
carbonic  oxide,  which  riddles  through  red-hot  iron,  is  a  real 
evil,  but  easily  obviated  by  proper  lining.  The  frizzling  of 
particles  of  organic  matter,  of  which  we  hear  so  much,  is —  if 
it  really  does  occur — highly  advantageous,  seeing  that  it  must 
destroy  organic  poison-germs. 

Under  some  conditions,  the  warm  air  of  a  room  does  deposit 
moisture  on  its  cooler  walls.  This  happens  in  churches,  con- 
cert-rooms, etc. ,  when  they  are  but  occasionally  used  in  winter 
time,  and  mainly  warmed  by  animal  heat,  by  congregational 
emanations  of  breath-vapor,  and  perspiration — i.e.  with  warm 
air  supersaturated  with  vapor?  Also,  when  we  have  a  sudden 
change  from  dry,  frosty  weather  to  warm  and  humid.  Then 
our  walls  may  be  streaming  with  condensed  water.  Such  cases 
were  probably  in  the  mind  of  Dr.  Siemens  when  he  spoke  ; 
but  they  are  quite  different  from  stove-heating  or  pipe-heating, 
which  increases  the  vapor  capacity  of  the  heated  air,  without 
supplying  the  demand  it  creates. 


CHAPTER  X. 

VENTILATION    BY    OPEN    FIREPLACES. 

THE  most  stubborn  of  all  errors  are  those  which  have  been 
acquired  by  a  sort  of  inheritance,  which  have  passed  dogmati- 
cally from  father  to  son,  or,  still  worse,  from  mother  to 
daughter.  They  may  become  superstitions  without  any  theo- 
logical character.  The  idea  that  the  weather  changes  with  the 
moon,  that  wind  "  keeps  off  the  rain,"  are  physical  super- 
stitions hi  all  cases  where  they  are  blindly  accepted  and  pro- 
mulgated without  any  examination  of  evidence. 

The  idea  that  our  open  fireplaces  are  necessary  for  ventilation 
is  one  of  these  physical  superstitions  which  is  producing  an  in- 
calculable amount  of  physical  mischief  throughout  Britain.  A 
little  rational  reflection  on  the  natural  and  necessary  movements 
of  our  household  atmospheres  demonstrates  at  once  that  this 
dogma  is  not  only  baseless,  but  actually  expresses  the  opposite 
of  the  truth.  I  think  I  shall  be  able  to  show  in  what  follows, 
1st,  that  they  do  no  useful  ventilation  ;  and,  2d,  that  they 
render  systematic  and  really  effective  ventilation  practically 
impossible. 

Everybody  knows  that  when  air  is  heated  it  expands  largely, 
becomes  lighter,  bulk  for  bulk,  than  other  air  of  lower  tem- 
perature ;  and  therefore,  if  two  portions  of  air  of  unequal 
temperatures,  and  free  to  move,  are  in  contact  with  each  other, 
the  colder  will  flow  under  the  warmer,  and  push  it  upward. 
The  latter  postulate  must  be  kept  distinctly  in  view,  for  the 
rising  of  warm  air  is  too  commonly  regarded  as  due  to  some 
direct  uprising  activity  or  skyward  affinity  of  its  own,  instead 
of  being  understood  as  an  indirect  result  of  gravitation.  It 
is  the  downfalling  of  the  cooler  air  that  causes  the  uprising  of 
the  warmer. 

Now,  let  us  see  what,  in  accordance  with  the  above-stated 
simple  laws,  must  happen  in  an  ordinary  English  apartment 
that  is  fitted,  as  usual,  with  one  or  more  windows  more  or  less 
leaky,  and  one  or  more  doors  in  like  condition,  and  a  hole  in 
the  wall  in  which  coal  is  burning  in  an  iron  cage  immediately 
beneath  a  shaft  that  rises  to  the  top  of  the  house  t  the  fire-hole 
itself  having  an  extreme  height  of  only  24  to  30  inches  above 
the  floor,  all  the  chimney  above  this  height  being  entirely 


VENTILATION   BY   OPEN   FIREPLACES.  (Jl 

closed.  (I  find  by  measurement  that  24  inches  is  the  usual 
height  of  the  upper  edge  of  the  chimney  opening  of  an  ordi- 
nary "  register"  stove.  Old  farm-house  fireplaces  are  open  to 
the  mantelpiece.) 

Now,  what  happens  when  a  heap  of  coal  is  burning  in  this 
hole  ?  Some  of  the  heat — from  10  to  20  percent.,  according 
to  the  construction  of  the  grate — is  radiated  into  the  room,  the 
rest  is  conveyed  by  an  ascending  current  of  air  up  the  chimney. 
As  this  ascending  current  is  rendered  visible  by  the  smoke 
entangled  with  it,  no  further  demonstration  of  its  existence  is 
needed. 

But  how  is  it  pushed  up  the  chimney  ?  Evidently  by  cooler 
air,  that  flows  into  the  room  from  somewhere,  and  which 
cooler  air  must  get  under  it  in  order  to  lift  it.  In  ordinary 
rooms  this  supply  of  air  is  entirely  dependent  upon  their  defec- 
tive construction — bad  joinery  ;  it  enters  only  by  the  crevices 
surrounding  the  ill-fitting  windows  and  doors,  no  specially 
designed  opening  being  made  for  it.  Usually  the  chief  inlet  is 
the  space  under  the  door,  through  which  pours  a  rivulet  of 
cold  air,  that  spreads  out  as  a  lake  upon  the  floor.  This  may 
easily  be  proved  by  holding  a  lighted  taper  in  front  of  the 
bottom  door-chink  when  the  window  and  other  door — if  any 
— are  closed,  and  the  fire  is  burning  briskly.  At  the  same 
time  more  or  less  of  cold  air  is  poured  in  at  the  top  and  the 
side  spaces  of  the  door  and  through  the  window-chinks.  The 
proportion  of  air  entering  by  these  depends  upon  the  capacity 
of  the  bottom  door-chink.  If  this  is  large  enough  it  will  do 
nearly  all  the  work,  otherwise  every  other  possible  leakage, 
including  the  key-hole,  contributes. 

But  what  is  the  path  of  the  air  which  enters  by  these  higher 
level  openings  ?  The  answer  to  this  is  supplied  at  once  by  the 
fact  that  such  air  being  colder  than  that  of  the  room,  it  must 
fall  immediately  it  enters.  The  rivulet  under  the  door  is  thus 
supplemented  by  cascades  pouring  down  from  the  top  and 
sides  of  the  door  and  the  top  and  sides  of  the  windows,  all 
being  tributaries  to  the  lake  of  cold  air  covering  the  floor. 

The  next  question  to  be  considered  is,  What  is  the  depth  of 
this  lake  ?  In  this,  as  in  every  other  such  accumulation  of 
either  air  or  water,  the  level  of  the  upper  surface  of  the  lake  is 
determined  by  that  of  its  outlet.  The  outlet  in  this  case  is  the 
chimney  hole,  through  which  all  the  overflow  pours  upward  ; 
and,  therefore,  the  surface  of  the  flowing  stratum  of  cold  air 
corresponds  with  the  upper  part  of  the  chimney  hole,  or  of  the 
register,  where  register  stoves  are  used. 


62  SCIENCE   IN   SHORT   CHAPTERS. 

Below  this  level  there  is  abundant  ventilation,  above  it  there 
is  none.  The  cat  that  sits  on  the  hearth-rug  has  an  abundant 
supply  of  fresh  air,  and  if  we  had  tracheal  breathing  apertures 
all  down  the  sides  of  our  bodies,  as  caterpillars  have,  those  on 
our  lower  extremities  might  enjoy  the  ventilation.  If  we 
squatted  on  the  ground  like  savages  something  might  be  said 
for  the  fire-hole  ventilator.  But  as  we  are  addicted  to  sitting 
on  chairs  that  raise  our  breathing  apparatus  considerably  above 
the  level  of  the  top  of  the  register,  the  maximum  efficiency  of 
the  flow  of  cold  air  in  the  lake  below  is  expressed  by  the  prev- 
alence of  chilblains  and  rheumatism.* 

The  atmosphere  in  which  our  heads  are  immersed  is  practi- 
cally stagnant  ;  the  radiations  from  the  fire,  plus  the  animal 
heat  from  our  bodies,  just  warm  it  sufficiently  to  enable  the 
cool  entering  air  to  push  it  upward  above  the  chimney  outlet 
and  the  surface  of  the  lower  moving  stratum,  and  to  keep  it 
there  in  a  condition  of  stagnation. 

If  anybody  doubts  the  correctness  of  this  description,  he  has 
only  to  sit  in  an  ordinary  English  room  where  a  good  fire  is 
burning  — the  doors  and  windows  closed,  as  usual — and  then  to 
blow  a  cloud  by  means  of  pipe,  cigar,  or  by  burning  brown 
paper  or  otherwise,  when  the  movements  below  and  the  stag- 
nation above,  which  I  have  described,  will  be  rendered  visible. 
If  there  is  nobody  moving  about  to  stir  the  air,  and  the  experi- 
ment is  fairly  made,  the  level  of  the  cool  lake  below  will  be 
distinctly  shown  by  the  clearing  away  of  the  smoke  up  to  the 
level  of  the  top  of  the  register  opening,  toward  which  it  may 
be  seen  to  sweep. 

Above  this  the  smoke-wreaths  will  remain  merely  waving 
about,  with  slight  movements  due  to  the  small  inequalities  of 
temperature  caused  by  the  fraction  of  heat  radiated  into  the 
room  from  the  front  of  the  fire.  These  movements  are  chiefly 
developed  near  the  door  and  windows,  where  the  above-men- 
tioned cascades  are  falling,  and  against  the  walls  and  furniture, 
where  feeble  convection  currents  are  rising,  due  to  the  radiant 
heat  absorbed  by  their  surfaces.  The  stagnation  is  the  most' 
complete  about  the  middle  of  the  room,  where  there  is  the 
greatest  bulk  of  vacant  air-space. 

AVhen  the  inlet  under  the  door  is  of  considerable  dimen- 


*  Since  the  above  was  written,  a  correspondent  in  Paris  tells  me 
that  a  caricature  exists,  representing  a  Frenchman  enjoying  an  open 
nre  by  standing  on  his  head  in  the  middle  of  the  room. 


VENTILATION   IX    OPEN   FIREPLACES.  G3 

sions,  there  may  be  some  escape  of  warmer  upper  air  at  the  top 
of  the  windows,  if  their  fitting  is  correspondingly  defective. 
These,  however,  are  mere  accidents  ;  they  are  not  a  part  of  the 
vaunted  chimney-hole  ventilation,  but  interferences  with  it. 

There  is  another  experiment  that  illustrates  the  absence  of 
ventilation  in  such  rooms  where  gas  is  burning.  It  is  that  of 
suspending  a  canary  in  a  cage  near  the  roof.  But  this  is 
cruel  ;  it  kills  the  bird.  It  would  be  a  more  satisfactory 
experiment  to  substitute  for  the  canary-bird  any  wingless 
biped  who,  after  reading  the  above,  still  maintains  that  our 
fire-holes  are  effective  ventilators. 

Not  only  are  the  fire-holes  worthless  and  mischievous  ventila- 
tors themselves,  but  they  render  efficient  ventilation  by  any 
other  means  practically  impossible.  The  "  Arnott's  ventila- 
tor" that  we  sometimes  see  applied  to  the  upper  part  of  chim- 
neys, is  marred  in  its  action  by  the  greedy  "  draught"  below. 

The  tall  chimney-shaft  with  a  fire  burning  immediately 
below  it  dominates  all  the  atmospheric  movement  in  the  house, 
unless  another  and  more  powerful  upcast  shaft  be  somewhere 
else  in  communication  with  the  apartments.  But  in  this  case 
the  original  or  ordinary  chimney  would  be  converted  into  a 
downcast  shaft  pouring  air  downward  into  the  room,  instead  of 
carrying  it  away  upward.  I  need  not  describe  the  sort  of  venti- 
lation thus  obtainable  while  the  fire  is  burning  and  smoking. 

Effective  sanitary  ventilation  should  supply  gentle  and  uni- 
formly diffused  currents  of  air  of  moderate  and  equal  tempera- 
ture throughout  the  house.  We  talk  a  great  deal  about  the 
climate  here  and  the  climate  there  ;  and  when  we  grow  old, 
and  can  afford  it,  we  move  to  Bournemouth,  Torquay,  Men- 
ton,  Nice,  Algiers,  etc.,  for  better  climates,  forgetting  all  the 
while  that  the  climate  in  which  we  practically  live  is  not  that 
out-of-doors,  but  the  indoor  climate  of  our  dwellings,  the 
which,  in  a  properly  constructed  house,  may  be  regulated  to 
correspond  to  that  of  any  latitude  we  may  choose.  I  maintain 
that  the  very  first  step  toward  the  best  attainable  approxima- 
tion to  this  in  our  existing  houses  is  to  brick  up,  cement  up, 
or  otherwise  completely  stop  up,  all  our  existing  fire-holes,  and 
abolish  all  our  existing  fires. 

But  what  next  ?  The  reply  to  this  will  be  found  in  the  next 
chapter. 


CHAPTER  XI. 

DOMESTIC    VENTILATION A    LESSON    FROM    THE    COAL-PITS. 

WE  require  in  our  houses  an  artificial  temperate  climate 
which  shall  be  uniform  throughout,  and  at  the  same  time  we 
need  a  gentle  movement  of  air  that  shall  supply  the  require- 
ments of  respiration  without  any  gusts,  or  draughts,  or  alter- 
nations of  temperature.  Everybody  will  admit  that  these  are 
fundamental  desiderata,  but  whoever  does  so  becomes  thereby 
a  denouncer  of  open-grate  fireplaces,  and  of  every  system  of 
heating  which  is  dependent  on  any  kind  of  stoves  with  fuel 
burning  in  the  rooms  that  are  to  be  inhabited.  All  such 
devices  concentrate  the  heat  in  one  part  of  each  room,  and 
demand  the  admission  of  cold  air  from  some  other  part  or 
parts,  thereby  violating  the  primary  condition  of  uniform 
temperature.  The  usual  proceeding  effects  a  specially  out- 
rageous violation  of  this,  as  I  showed  in  the  last  chapter. 
y  I  might  have  added  domestic  cleanliness  among  the  deside- 
rata ;  but  in  the  matter  of  fireplaces  the  true-born  Briton,  in 
spite  of  his  fastidiousness  in  respect  to  shirt-collars,  etc.,  is  a 
devoted  worshipper  of  dirt.  No  matter  how  elegant  his  draw- 
ing-room, he  must  defile  it  with  a  coal-scuttle,  with  dirty 
coals,  poker,  shovel,  and  tongs,  dirty  ash-pit,  dirty  cinders, 
ashes,  arid  dust,  and  he  must  amuse  himself  by  doing  the  dirty 
work  of  a  stoker  toward  his  "  cheerful,  companionable,  poke- 
able"  open  fire. 

It  is  evident  that,  in  order  to  completely  fulfil  the  first- 
named  requirements,  we  must,  in  winter,  supply  our  model 
residence  with  fresh  artificially  warmed  air,  and  in  summer 
with  fresh  cool  air.  How  is  this  to  be  done  ?  An  approach 
to  a  practical  solution  is  afforded  by  examining  what  is  actually 
done  under  circumstances  where  the  ventilation  problem  pre- 
sents the  greatest  possible  difficulties,  and  where,  nevertheless, 
these  difficulties  have  been  effectually  overcome.  Such  a  case 
is  presented  by  a  deep  coal  mine.  Here  we  have  a  little 
working  world,  inhabited  by  men  and  horses,  deep  in  the 
bowels  of  the  earth,  far  away  from  the  air  that  must  be  sup- 
plied in  sufficient  quantities,  not  only  to  overcome  the  vitiation 
due  to  their  own  breathing,  but  also  to  sweep  out  the  deadly 
gaseous  emanations  from  the  coal  itself. 


DOMESTIC    VENTILATION.  65 


Imagine  your  dwelling-house  buried  a  quarter  of  a  mile  of 
perpendicular  depth  below  the  surface  of  the  earth,  and  its  walls 
giving  off  suffocating*  and  explosive  gases  in  such  quantities 
that  steady  and  abundant  ventilation  shall  be  a  matter  of  life 
or  death,  and  that  in  spite  of  this  it  is  made  so  far  habitable 
that  men  who  spend  half  their  days  there  retain  robust  health 
and  live  to  green  old  age,  and  that  horses,  after  remaining  there- 
day  and  night  for  many  months,  actually  improve  in  condition. 
Imagine,  further,  that  the  house  thus  ventilated  has  some 
hundreds  of  small,  very  low-roofed  rooms,  and  a  system  of 
passages  or  corridors  with  a  united  length  of  many  miles, 
and  that  its  inhabitants  count  by  hundreds. 

Such  dwellings  being  thus  ventilated  and  rendered  habi- 
table for  man  and  beast,  it  is  idle  to  dispute  the  practical  possi- 
bility of  supplying  fresh  air  of  any  given  temperature  to  a 
mere  box  of  brick  or  stone,  standing  in  the  midst  of  the 
atmosphere,  and  containing  but  a  few  passages  and  apartments. 

The  problem  is  solved  in  the  coal-pit  by  simple  and  skilfully 
controlling  and  directing  the  natural  movements  of  unequally 
heated  volumes  of  air.  Complex  mechanical  t devices  for  forc- 
ing the  ventilation  by  means  of  gigantic  fan- wheels,  etc.,  <£• 
by  steam-jets,  have  been  tried,  and  are  now  generally  aban- 
doned. An  inlet  and  an  outlet  are  provided,  and  no  air  is 
allowed  to  pass  inward  or  outward  by  any  other  course  than 
that  which  has  been  pre-arranged  for  the  purposes  of  efficient 
ventilation.  I  place  especial  emphasis  on  this  condition, 
believing  that  its  systematic  violation  is  the  primary  cause  of 
the  bungling  muddle  of  our  domestic  ventilation. 

Let  us  suppose  that  we  are  going  to  open  a  coal-pit  to  win 
the  coal  on  a  certain  estate.  We  first  ascertain  the  "  dip" 
of  the  seam,  or  its  deviation  from  horizontality,  and  then  start 
at  the  loioest  part,  not,  as  some  suppose,  at  that  part  nearest 
to  the  surface.  The  reason  for  this  is  obvious  on  a  little  reflec- 
tion, for  if  we  began  at  the  shallowest  part  of  an  ordinary 
water-bearing  stratum  we  should  have  to  drive  down  under 
water  ;  but,  by  beginning  at  the  lowest  part  and  driving  up- 
ward, we  can  at  once  form  a  "  surapf  "  or  bottom  receptacle, 
to  receive  the  drainage,  and  from  which  the  accumulated 
water  may  be  pumped.  This,  however,  is  only  by  the  way, 
and  not  directly  connected  with  our  main  subject,  the  venti- 
lation. 

In  order  to  secure  this,  the  modern  practice  is  to  sink  two 
pits,  "  a  pair,"  as  they  are  called,  side  by  side,  at  any  con- 


CO  SCIENCE    IN    SHORT   CHAPTERS. 

venient  distance  from  each  other.  If  they  are  deep,  it 
becomes  necessary  to  commence  ventilation  of  the  mere  shafts 
themselves  in  the  course  of  sinking.  This  is  done  by  driving 
an  air- way — a  horizontal  tunnel  from  one  to  the  other,  and 
then  establishing  an  "  upcast"  in  one  of  them  by  simply 
lighting  a  fire  there.  This  destroys  the  balance  between  the 
two  communicating  columns  of  air  ;  the  cooler  column  in  the 
shaft  without  a  fire,  being  heavier,  falls  against  the  lighter 
column,  and  pushes  -it  up  just  as  the  air  is  pushed  up  one  leg 
of  an  U  tube  when  we  pour  water  down  the  other.  Even  in 
this  preliminary  work,  if  the  pits  are  so  deep  that  more  than 
one  air- way  is  driven,  it  is  necessary  to  stop  the  upper  ways 
and  leave  only  the  lowest  open,  in  order  that  the  ventilation 
shall  not  take  a  short  and  useless  cut,  as  it  does  up  our  fire- 
place openings. 

Let  us  now  suppose  that  the  pair  of  pits  are  sunk  down  to 
the  seam,  with  a  further  extension  below  to  form  the  water 
stimpf.  There  are  two  chief  modes  of  working  a  coal-seam, 
the  "  pillar  and  stall  "  and  the  "  long  wall,"  or  more  modern 
system.  For  present  illustration,  I  select  the  latter  as  the 
simplest  in  respect  to  ventilation.  This  method,  as  ordinarily 
worked,  consists  essentially  in  first  driving  roads  through  the 
coal,  from  the  pits  to  the  outer  boundary  of  the  area  to  be 
worked,  then  cutting  a  cross-road  that  shall  connect  these, 
thereby  exposing  a  **  long  wall  "  of  coal,  which,  in  working, 
is  gradually  cut  away  toward  the  pits,  the  roof  remaining 
behind  being  allowed  to  fall  in. 

Let  us  begin  to  do  this  by  driving,  first  of  all,  two  main 
roads,  one  from  each  pit.  It  is  evident  that  as  we  proceed  in 
such  burrowing,  we  shall  presently  find  ourselves  in  a  cul  de 
sac  so  far  away  from  the  outer  air  that  suffocation  is  threaten- 
ed. This  will  be  equally  the  case  with  both  roads.  Let  us 
now  drive  a  cross-cut  from  the  end  of  each  main  road,  and 
thus  establish  a  communication  from  the  downcast  shaft 
through  its  road,  then  through  the  drift  to  the  upcast  road  and 
pit.  But  in  'order  that  the  air  shall  take  this  roundabout 
course,  we  must  close  the  direct  drift  that  we  previously  made 
between  the  two  shafts,  or  it  will  proceed  by  that  shorter  and 
easier  course.  Now,  we  shall  have  air  throughout  both  our 
main  roads,  and  we  may  drive  on  further  until  we  are  again 
stopped  by  approximate  suffocation.  When  this  occurs,  we 
make  another  cross-cut,  but  in  order  that  it  may  act,  we 
must  stop  the  first  one.  So  we  go  on  until  we  reach  the  work- 


DOMESTIC    VEXTILATIOJST.  G< 

ing,  and  then  th©  long  wall  itself  becomes  the  cross  communi- 
cation, and  through  this  working-gallery  the  air  sweeps  freely 
and  effectually. 

In  the  above  I  have  only  considered  the  simplest  possible 
elements  of  the  problem.  The  practical  coalpit  in  full  work- 
ing has  a  multitude  of  intervening  passages  and  "  splits," 
where  the  main  current  from  the  downcast  is  divided,  in  order 
to  proceed  through  the  various  streets  and  lanes  of  the  sub- 
terranean town  as  may  be  required,  and  these  divided  currents 
are  finally  reunited  ere  they  reach  the  upcast  shaft  which  casts 
them  all  out  into  the  upper  air. 

In  a  colliery  worked  on  the  pillar  and  stall  system — i.e.  by 
taking  out  the  coal  so  as  to  leave  a  series  of  square  chambers 
with  pillars  of  coal  in  the  middle  to  support  the  roof — the 
windings  of  the  air  between  the  multitude  of  passages  is 
curiously  complex,  and  its  absolute  obedience  to  the  commands 
of  the  mining  engineer  proves  how  completely  the  most  diffi- 
cult problems  of  ventilation  may  be  solved  when  ignorance  and 
prejudice  are  not  permitted  to  bar  the  progress  of  the  practi- 
cal applications  of  simple  scientific  principles. 

Here  the  necessity  of  closing  all  false  outlets  is  strikingly 
demonstrated  by  the  mechanism  and  working  of  the  "  stop- 
pings" or  partitions  that  close  all  unrequired  openings.  The 
air  in  many  pits  has  to  travel  several  miles  in  order  to  get 
from  the  downcast  to  the  upcast  shaft,  though  they  may  be 
but  a  dozen  yards  apart.  (Formerly  the  same  -shaft  served 
both  for  up  and  down  cast,  by  making  a  wooden  division  (a 
brattice)  down  the  middle.  This  is  now  prohibited,  on 
account  of  serious  accidents  that  have  been  caused  by  the  fract- 
ure of  the  brattice). 

But  it  would  not  do  to  carry  the  coal  from  the  workings  to 
the  pit  by  these  sinuous  air-courses.  What,  then,  is  done  ? 
A  direct  road  is  made  for  the  coal,  but  if  it  were  left  open,  the 
air  would  choose  it  :  this  is  prevented  by  an  arrangement  sim- 
ilar to  that  of  canal  locks.  Valve-doors  or  "  stoppings"  arc 
arranged  in  pairs,  and  when  the  "  hurrier"  arrives  with  his 
curve,  or  pit  carriage,  one  door  is  opened,  the  other  remain- 
ing shut ;  then  the  corve  is  hurried  into  the  space  between 
the  doors,  and  the  entry-door  is  closed  ;  now  the  exit- 
door  is  opened,  and  thus  no  continuous  opening  is  ever  per- 
mitted. - 

Only  one  such  opening  would  derange  the  ventilation  of  the 
whole  pit,  or  of  that  portion  fed  by  the  split  thus  allowed  to 


OS  SCIENCE    IN   SHORT   CHAPTERS. 

escape.  It  would,  in  fact,  correspond  to  the  action  of  our 
open  fireplaces  in  rendering  effective  ventilation  impossible. 

The  following,  from  the  report  of  the  Lords'  Committee 
on  Accidents  in  Coal  Mines,  1849,  illustrates  the  magnitude 
of  the  ventilation  arrangements  then  at  work.  In  the  Helton 
Colliery  there  were  two  downcast  shafts  and  one  upcast,  the 
former  about  12  feet  and  the  latter  14  feet  diameter.  There 
wore  three  furnaces  at  the  bottom  of  the  upcast,  each  about  9 
feet  wide  with  about  4  feet  length  of  grate-bars  ;  the  depth 
of  the  upcast  and  one  downcast  900  feet,  and  of  the  other 
downcast  1056  feet.  The  quantity  of  air  introduced  by  the 
action  of  these  furnaces  was  168,560  cubic  feet  per  minute,  at 
a  cost  of  about  eight  tons  of  coal  per  day.  The  rate  of  motion 
of  the  air  was  1097  feet  per  minute  (above  12  miles  per  hour). 
This  whole  current  was  divided  by  splitting  into  16  currents  of 
about  11,000  cubic  feet  each  per  minute,  having,  on  an  aver- 
age, a  course  of  4J  miles  each.  This  distance  was,  however, 
very  irregular — the  greatest  length  of  a  course  being  9^  miles  ; 
total  length,  70  miles.  Thus,  168,560  cubic  feet  of  air  were 
driven  through  these  great  distances  at  the  rate  of  12  miles  per 
hour,  and  at  a  cost  of  8  tons  of  coal  per  day. 

All  these  magnitudes  are  greatly  increased  in  coal-mines  of 
the  present  time.  As  much  as  250,000  cubic  feet  of  air  per 
minute  are  now  passed  through  the  shafts  of  one  mine. 

The  problem  of  domestic  ventilation  as  compared  with  coal- 
pit ventilation  involves  an  additional  requirement,  that  of 
warming,  but  this  does  not  at  all  increase  the  difficulty,  and  I 
even  go  so  far  as  to  believe  that  cooling  in  summer  may  be 
added  to  warming  in  winter  by  one  and  the  same  ventilating 
arrangement.  As  I  am  not  a  builder,  and  claim  no  patent 
rights,  the  following  must  be  regarded  as  a  general  indication, 
not  as  a  working  specification,  of  my  scheme  for  domestic 
ventilation  and  the  regulation  of  home  climate. 

The  model  house  must  have  an  upcast  shaft,  placed  as 
nearly  in  the  middle  of  the  building  as  possible,  with  which 
every  room  must  communicate  either  by  a  direct  opening  or 
through  a  lateral  shaft.  An  ordinary  chimney  built  in  the 
usual  manner  is  all  that  is  required  to  form  such  a  main  shaft. 

There  must  be  no  stoves  nor  any  fireplaces  in  any  room 
excepting  the  kitchen,  of  which  anon.  All  the  windows  must 
be  made  to  fit  closely,  as  nearly  air-tight  as  possible.  No 
downcast  shaft  is  required,  the  pressure  of  the  surrounding 
outer  atmosphere  being  sufficient.  Outside  of  the  house,  or 


DOMESTIC    VENTILATION.  01) 

on  the  ground-floor  (on  the  north  side,  if  possible),  should  be 
a  chamber  heated  by  flues,  hot  air,  steam,  a  suitable  stove,  or 
water-pipes,  and  with  one  adjustable  opening  communicating 
with  the  outer  fresh  air,  and  another  on  the  opposite  side  con- 
nected by  a  shaft  or  airway  with  the  hall  of  the  ground-floor 
and  the  general  staircase. 

Each  room  to  have  an  opening  at  its  upper  part  communicat- 
ing with  the  chimney,  like  an  Arnott's  ventilator,  and  capable 
of  adjustment  as  regards  area  of  aperture,  and  other  openings 
of  corresponding  or  excessive  combined  area  leading  from  the 
hall  or  staircase  to  the  lower  part  of  the  room.  These  may  be 
covered  with  perforated  zinc  or  wire  gauze,  so  that  the  air 
may  enter  in  a  gentle,  broken  stream. 

All  the  outer  house-doors  must  be  double — i.e.  with  a  porch 
or  vestibule — and  only  one  of  each  pair  of  doors  opened  at 
once.  These  should  be  well  fitted,  and  the  staircase  air-tight. 
The  kitchen  to  communicate  with  the  rest  of  the  house  by 
similar  double  doors,  and  the  kitchen  fire  to  communicate 
directly  with  the  upcast  shaft  or  chimney  by  as  small  a  stove- 
pipe as  practicable.  The  kitchen  fire  will  thus  start  the  upcast 
and  commence  the  draught  of  air  from  the  warm  chamber 
through  the  house  toward  the  several  openings  into  the  shaft. 
In  cold  weather  this  upcast  action  will  be  greatly  reinforced 
and  maintained  by  the  general  warmth  of  all  the  air  in  the 
house,  which  itself  will  bodily  become  an  upcast  shaft  im- 
me-diately  the  inner  temperature  exceeds  that  of  the  air  out- 
side. 

But  the  upcast  of  warm  air  can  only  take  place  by  the  admis- 
sion of  fresh  air  through  the  heating  chamber,  thence  to^  hall 
and  staircase,  and  thence  onward  through  the  rooms  into  the 
final  shaft  or  chimney. 

The  openings  into  and  out  of  the  rooms  being  adjustable, 
they  may  be  so  regulated  that  each  shall  receive  an  equal 
share  of  fresh  warm  air  ;  or,  if  desired,  the  bedroom  chimney 
valves  may  be  closed  in  the  daytime,  and  thus  the  heat  econ- 
omized by  being  used  only  for  the  day  rooms  ;  or  vice  versa, 
the  communication  between  the  upcast  shaft  and  the  lower 
rooms  may  be  closed  in  the  evening,  and  thus  all  the  warm  air 
be  turned  into  the  bedrooms  at  bedtime. 

If  the  area  of  the  entrance  apertures  of  the  rooms  exceeds 
that  of  the  outlet,  only  the  latter  need  be  adjusted  ;  the  room 
doors  may,  in  fact,  be  left  wide  open  without  any  possibility 
of  "  draught,"  beyond  the  ventilation  current,  which  is  limited 


70  SCIENCE  I:NT  SHORT  CHAPTERS. 

by  the  dimensions  of  the  opening  from  the  room  into  the  shaft 
or  chimney. 

So  far  for  winter  time,  when  the  ventilation  problem  is  the 
easiest,  because  then  the  excess  of  inner  warmth  converts  the 
whole  house  into  an  upcast  shaft,  and  the  whole  outer  atmos- 
phere becomes  a  downcast.  In  the  summer  time,  the  kitchen 
tire  would  probably  be  insufficient  to  secure  a  sufficiently  active 
upcast. 

To  help  this  there  should  be  in  one  of  the  upper  rooms — say 
an  attic — an  opening  into  the  chimney  secured  by  a  small  well- 
fitting  door  ;  and  altogether  inclosed  within  the  chimney,  a 
small  automatic  slow-combustion  stove  (of  which  many  were 
exhibited  at  South  Kensington,  that  require  feeding  but  once 
in  twenty-four  hours),  or  a  large  gas-burner.  The  heating- 
chamber  below  must  now  be  converted  into  a  cooling- chamber 
by  an  arrangement  of  wet  cloths,  presently  to  be  described,  so 
that  all  the  air  entering  the  house  shall  be  reduced  in  tempera- 
ture. 

Or  the  winter  course  of  ventilation  may  be  reversed  by 
building  a  special  shaft  connected  with  the  kitchen  fire,  which, 
in  this  case,  must  not  communicate  with  the  house  shaft. 
This  special  shaft  may  thus  be  made  an  upcast,  and  the  rooms 
supplied  with  air  from  above  down  the  house  shaft,  through 
the  rooms,  and  out  of  the  kitchen  via  the  winter  heating- 
chamber,  which  now  has  its  communication  with  the  outside 
air  closed. 

Reverting  to  the  first-named  method,  which  I  think  is  better 
than  the  second,  besides  being  less  expensive,  I  must  say  a  few 
concluding  words  on  an  important  supplementary  advantage 
which  is  obtainable  wherever  all  the  air  entering  the  house 
passes  through  one  opening,  completely  under  control,  like  that 
of  our  heating-chamber.  The  great  evil  of  our  town  atmos- 
phere is  its  dirtiness.  In  the  winter  it  is  polluted  with  soot 
particles  ;  in  the  dry  summer  weather,  the  traffic  and  the  wind 
stir  up  and  mix  with  it  particles  of  dust,  having  a  composition 
that  is  better  ignored,  when  we  consider  the  quantity  of  horse- 
dung  that  is  dried  and  pulverized  on  our  roadways.  All  the 
dust  that  falls  on  our  books  and  furniture  was  first  suspended 
in  the  air  we  breathe  inside  our  rooms.  Can  we  get  rid  of  any 
practically  important  portion  of  this  ? 

I  am  able  to  answer  this  question,  not  merely  on  theoretical 
grounds,  but  as  a  result  of  practical  experiments  described  in 
the  following  chapter,  in  which  is  reprinted  a  paper  I  read  at 


DOMESTIC   VENTILATION.  71 

the  Society  of  Arts,  March  19th,  1879,  recommending  the 
inclosure  of  London  backyards  with  a  roofing  of  "  wall 
canvas,"  or  "  paper-hanger's  canvas,"  so  as  to  form  cheap 
conservatories.  This  canvas,  which  costs  about  threepence  per 
square  yard,  is  a  kind  of  coarse,  strong,  fluffy  gauze,  admitting 
light  and  air,  but  acting  very  effectively  as  an  air  filter,  by 
catching  and  stopping  the  particles  of  soot  and  dust  that  are  so 
fatal  to  urban  vegetation. 

I  propose,  therefore,  that  this  well-tried  device  should  be 
applied  at  the  entrance  aperture  of  our  heating-chamber,  that 
the  screens  shall  be  well  wetted  in  the  summer,  in  order  to 
obtain  the  cooling  effect  of  evaporation,  and  in  the  winter  shall 
be  either  wet  or  dry,  as  may  be  found  desirable.  The  Parlia- 
ment House  experiments  prove  that  they  are  good  filters  when 
wetted,  and  mine  that  they  act  similarly  when  dry. 

By  thus  applying  the  principles  of  colliery  ventilation  to  a 
specially  constructed  house,  we  may,  I  believe,  obtain  a  per- 
fectly controllable  indoor  climate,  with  a  range  of  variation  not 
exceeding  four  or  five  degrees  between  the  warmest  and  the 
coldest  part  of  the  house,  or  eight  or  nine  degrees  between 
summer  and  winter,  and  this  may  be  combined  with  an  abun- 
dant supply  of  fresh  air  everywhere,  all  filtered  from  the  grosser 
portions  of  its  irritant  dust,  which  is  positively  poisonous  to 
delicate  lungs,  and  damaging  to  all.  The  cost  of  fuel  would 
be  far  less  than  with  existing  arrangements,  and  the  labor  of 
attending  to  one  or  two  fires  and  the  valves  would  also  be  l3ss 
than  that  now  required  in  the  carrying  of  coal-scuttles,  the 
removal  of  ashes,  the  cleaning  of  fireplaces,  and  the  curtains 
and  furniture  they  befoul  by  their  escaping  dust  and  smoke. 

It  is  obvious  that  such  a  system  of  ventilation  may  evea  be 
applied  to  existing  houses  by  mending  the  ill-fitting  windows, 
slmtting  up  the  existing  fire-holes,  and  using  the  chimneys  as 
upcast  shafts  in  the  manner  above  described.  This  may  be 
done  in  the  winter,  when  the  problem  is  easiest,  and  the 
demand  for  artificial  climate  the  most  urgent  ;  but  I  question 
the  possibility  of  summer  ventilation  and  tempering  of  climate 
in  anything  short  of  a  specially  built  house  or  a  materially 
altered  existing  dwelling.  There  are  doubtless  some  exceptions 
to  this,  where  the  house  happens  to  be  specially  suitable  and 
easily  adapted,  but  in  ordinary  houses  we  must  be  content 
with  the  ordinary  devices  of  summer  ventilation  by  doors  an4 
windows,  plus  the  upper  openings  of  the  rooms  into  the  chim- 
neys expanded  to  their  full  capacity,  and  thus  doing,  even  iu 


72  SCIENCE   IK    SHORT   CHAPTERS. 

summer,  far  better  ventilating  work  than  the  existing  lire-holes 
opening  in  the  wrong  place. 

I  thus  expound  my  own  scheme,  not  because  I  believe  it  to 
be  perfect,  but,  on  the  contrary,  as  a  suggestive  project  to  be 
practically  amended  and  adapted  by  others  better  able  than  my- 
self to  carry  out  the  details.  The  feature  that  I  think  is  novel 
;md  important  is  that  of  consciously  and  avowedly  applying  to 
domestic  ventilation  the  principles  that  have  been  so  success- 
fully carried  out  in  the  far  more  difficult  problem  of  subter- 
ranean ventilation. 

The  dishonesty  of  the  majority  of  the  modern  builders  of 
surburban  "  villa  residences"  is  favorable  to  this  and  other 
similar  radical  household  reforms,  as  thousands  of  these 
wretched  tenements  must  sooner  or  later  be  pulled  down,  or 
will  all  come  down  together  without  any  pulling  the  next  time 
we  experience  one  of  those  earthquake  tremors  which  visit 
England  about  once  in  a  century. 


CHAPTER  XIT. 

THE    FUEL    OF    THE    SUN. 

I  OFFER  the  following  sketch  of  the  main  argument  which  is 
worked  out  more  fully  in  the  essay  I  published  in  January 
1870,  Tinder  the  above  title,  hoping  that  many  who  hesitate  to 
plunge  into  a  presumptuous  speculative  work  of  more  than  200 
octavo  pages  ma}^  read  this  article,  and  reflect  upon  the  subject. 

The  book  has  been  handled  in  a  most  courteous  and  indul- 
gent spirit  by  all  the  reviewers  who  have  noticed  it,  but  none 
have  ventured  to  grapple  with  the  argument  it  contains, 
although  every  possible  opportunity  and  provocation  for  doing 
so  is  designedly  afforded.  It  all  rests  upon  the  question  which 
is  discussed  in  the  first  three  chapters — viz.,  Whether  the 
atmospnere  which  surrounds  our  earth  is  limited  or  unlimited 
in  extent  ?  If  my  reasoning  upon  this  fundamental  question 
is  refuted,  all  that  follows  necessarily  falls  to  the  ground.  If  I 
am  right,  all  our  standard  treatises  on  pneumatics  and  meteor- 
ology, which  repeat  the  arguments  contained  in  Dr.  Wollaston's 
celebrated  paper,  must  be  remodelled.  At  the  outset,  I 


THE   FUEL   OF   THE   SUX.  73 

reprint  that  paper,  and  point  out  a  very  curious  and  monstrous 
fallacy  \vhich,  for  half  a  century,  remained  undetected,  and 
had  been  continually  repeated. 

As  the  main  point  of  issue  between  myself  and  Dr.  Wollas- 
ton  is  merely  a  question  of  very  simple  arithmetic  and  geom- 
etry, nothing  can  be  easier  than  to  set  me  right  if  I  am 
wrong  ;  and,  as  the  philosophical  consequences  depending 
upon  this  issue  are  of  vast  and  fundamental  importance,  the 
question  cannot  be  ignored  by  those  who  stand  before  the 
world  as  scientific  authorities,  without  a  practical  abdication  of 
their  philosophical  responsibilities.  Any  man  who  publishes 
an  astronomical  or  meteorological  treatise  without  discussing  this 
question,  which  stands  before  him  at  the  threshold  of  his  sub- 
ject, is  unfit  for  the  task  he  has  undertaken,  and  unworthy  of 
public  confidence.  This  may  appear  a  strong  conclusion  just 
now,  but  a  few  years  will  be  sufficient  to  graft  it  firmly  into 
the  growth  of  scientific  public  opinion.* 

"  The  Fuel  of  the  Sun"  is  simply  an  attempt  to  trace  some 
of  the  consequences  which  must  of  necessity  result  from  the 
existence  of  a  universal  atmosphere,  and  it  differs  from  other 
attempts  to  explain  the  great  solar  mystery,  by  making  no 
demands  whatever  upon  the  imagination,  inventing  nothing — 
no  outside  meteors,  no  new  forces  or  materials.  It  supposes 
nothing  whatever  to  exist  but  the  known  facts  of  the  labora- 
tory— the  familiar  materials  of  the  earth  and  its  atmosphere. 
It  is  shown  that  these  materials  and  the  forces  residing  within 
them  must  of  necessity  produce  a  sun,  and  manifest  eternally 
all  the  observed  solar  phenomena,  provided  only  they  are  aggre- 
gated in  the  quantities  which  our  own  central  luminary  pre- 
sents, and  are  surrounded  by  attended  planets  such  as  his. 
Nothing  is  assumed  or  taken  for  granted  beyond  the  simple 
fundamental  hypothesis  that  the  laws  of  nature  are  uniform 
throughout  the  universe.  The  argument  thus  conducted  leads 
us  step  by  step  to  a  natural  and  connected  explanation  of  the 
ollowing  important  phenomena  : 

*  Up  to  the  present  date  (1882)  nobody,  as  far  as  I  know,  has 
questioned  my  figures  or  defended  those  of  Wollaston's.  Sir  William 
Grove  has  written  to  me,  pointing  out  his  own  anticipations  of  my 
conclusions  respecting  the  universality  of  atmospheric  matter.  Sir 
Charles  Lyell,  before  his  death,  expressed  very  strong  approval  of  my 
conclusions,  and  many  other  men  of  scientific  eminence  have  done 
the  same.  To  expect  any  immediate,  unreserved  adoption  of  such 
bold  speculations  would  be  unreasonable.  - 


74  SCIENCE   IN   SHORT   CHAPTEKS. 

1.  The  sources  of  solar  and  stellar  heat  and  light. 

2.  The  means  by  which  the  present  amount  of  solar  heat 
and  light  must  be  maintained  so  long  as  the  solar  system  con- 
tinues in  existence. 

3.  The  origin  of  the  general  and  particular  phenomena  of 
the  sun-spots. 

4.  The  cause  of  the  varying  splendor  of  the  photosphere, 
including  such  details  as  the  **  faculse,"  "  mottling,"  "  granu- 
lations," etc.,  etc. 

5.  The  forces  which  upheave  the  solar  prominences. 
G.   The  origin  of  the  corona  and  zodiacal  light. 

7.  The  origin  of  the  meteorites  and  the  asteroids. 

8.  The  meteorological  phenomena  of  the  planets. 
0.  The  origin  of  the  rings  of  Saturn. 

10.  The  origin  of  the  special  structure  of  the  nebulae. 

11.  The  source  of  terrestrial  magnetism,  and  its  connection 
with  solar  activity. 

The  first  and  second  chapters  are  devoted  to  an  examination 
of  the  limits  of  atmospheric  expansibility.  The  experimental 
investigations  of  Dr.  Andrews,  Mr.  Grove,  Mr.  Gassiot,  and 
M.  Geissler  arc  cited  to  prove  that  the  expansibility  of  the 
atmosphere  is  unlimited,  and  other  cosmical  evidence  is 
adduced  in  support  of  this  conclusion. 

As  this,  which  is  really  the  foundation  of  the  whole  argu- 
ment, is  directly  opposed  to  the  views  expressed  by  Dr. 
AVollaston,  in  his  celebrated  paper  on  **  The  Finite  Extent  of 
the  Atmosphere,"  published  in  1822,  and  generally  accepted 
as  established  science,  1his  paper  is  reprinted  in  the  second 
chapter,  and  carefully  examined. 

Dr.  Wollaston  says  "  that  air  has  been  rarefied  so  as  to 
sustain  1-1 00th  of  an  inch  of  barometrical  pressure,"  and 
further,  that  4t  beyond  this  limit  we  are  left  to  conjectures 
founded  on  the  supposed  divisibility  of  matter  ;  if  this  be 
infinite,  so  also  must  be  the  extent  of  our  atmosphere." 

I  contend  that  our  knowledge  of  the  whole  subject  is  funda- 
mentally altered  since  these  words  were  written.  We  are  no 
longer  "  left  to  conjectures  founded  on  the  supposed  divisibil- 
ity of  matter"  to  determine  the  possibility  of  further  expansi- 
bility than  that  indicated  by  l-100th  of  an  inch  of  barometrical 
pressure,  as  we  now  have  means  of  obtaining  ten  times,  a 
hundred  times,  a  thousand  times,  or  even  an  infinitely  greater 
rarefaction  than  Wollaston's  supposed  limit,  an  apparently 
absolute  vacuum  being  now  obtainable  ;  and  although  the 


THE    FUEL   OF   THE   SUX.  »O 

transmission  of  electricity  affords  a  means  of  testing  the  exist- 
ence of  atmospheric  matter  with  a  degree  of  delicacy  of  which 
Wollaston  had  no  conception,  we  are  still  unable  to  detect  any 
indication  of  any  limit  to  its  expansibility. 

The  most  remarkable  part  of  Dr.  Wollaston's  paper  is  the 
reductio  ad  absurdum  by  which  he  seeks  to  finally  demonstrate 
the  finite  extent  of  our  atmosphere.  He  maintains,  as  I  do, 
that  if  the  elasticity  of  our  atmosphere  is  unlimited,  its  exten- 
sion must  be  commensurate  with  the  universe,  1hat  every  orb 
in  space  will,  by  gravitation,  gather  around  itself  an  atmosphere 
proportionarc  to  its  gravitating  power,  and  that,  by  taking  the 
known  quantity  of  the  earth's  atmosphere  as  our  unit,  we  may 
calculate  the  amount  of  atmosphere  possessed  by  any  heavenly 
body  of  which  the  mass  is  known.  On  this  basis  Dr.  Wollas- 
ton calculates  the  atmosphere  of  the  sun,  and  concludes  that  its 
extent  will  be  so  great  as  to  visibly  affect  the  apparent  motions 
of  Mercury  and  Venus,  when  their  declination  makes  its 
nearest  approach  to  that  of  the  sun.  No  such  disturbance 
being  actually  observable,  he  concludes  that  such  an  atmos- 
phere as  he  has  calculated  cannot  exist.  In  like  manner  he 
calculates  the  atmosphere  of  Jupiter,  and  finds  it  to  be  so  great 
that  its  refraction  would  be  sufficient  "  to  render  the  fourth 
satellite  visible  to  us  when  behind  the  centre  of  the  planet,  and 
consequently  to  make  it  appear  on  both  (or  all)  sides  at  the 
same  time." 

^On  examining  these  calculations,  I  have  discovered  the  very 
curious  error  above  referred  to.  As  this  is  a  matter  of  figures 
that  cannot  be  abridged,  I  must  refer  the  reader  to  the  original 
calculations.  I  will  here  merely  state  that  Wollaston's 
method  of  calculating  the  solar  gravitation  atmosphere  and  that 
of  Jupiter  and  the  moon  leads  to  the  monstrous  conclusion 
that,  in  ascending  from  the  surface  of  the  given  orb,  we  always 
have  the  same  limited  amount  of  atmospheric  matter  above  as 
that  with  which  we  started,  although  we  are  continually  leav- 
ing a  portion  of  it  below. 

Wollaston's  mistake  is  based  on  the  assumption  that,  under 
the  circumstances  supposed,  the  atmospheric  pressure  and  den- 
sity, at  any  given  distance  from  the  centre  of  the  given  orb, 
will  vary  inversely  with  the  square  of  that  distance.  As  the 
area  of  the  base  upon  which  such  pressure  is  exerted  varies 
directly  with  the  square  of  the  distance,  the  total  atmosphere 
above  every  imaginable  starting-distance  would  thus  be  ever 
the  same.  That  this  assumption,  so  utterly  at  variance  with 


70  SCIENCE    IN    SHORT    CHAPTERS. 

tlic  known  laws  of  atmospheric  distribution,  should  have 
remained  unchallenged  for  half  a  century,  and  that  the  con- 
clusions based  upon  it  should  be  accepted  by  the  whole  scien- 
tific world,  and  repeated  in  standard  treatises,  such  as  those  of 
the  "  Encyclopedia  Britannica,"  etc.,  etc.,  is,  I  think,  one  of 
the  most  remarkable  curiosities  presented  by  the  history  of 
science.  If  it  were  merely  a  little  cobweb  in  some  obscure 
corner  of  philosophy,  there  would  be  nothing  surprising  in  its 
escape  from  the  besom  of  scientific  criticism  ;  but  this  is  so 
far  from  being  the  case,  that  it  has  hung,  since  1822,  like  a 
dark  veil  obscuring  another,  a  wider,  and  more  interesting 
view  of  the  universe  which  the  idea  of  a  universal  atmosphere 
opens  out.  But  I  must  now  proceed  to  the  next  stage  of  the 
argument. 

Starting  from  the  conclusion  reached  in  the  previous  chap- 
ters, that  the  atmosphere  of  our  earth  is  but  a  portion  of  a 
universal  elastic  medium  which  it  has  attached  to  itself  by  its 
gravitation,  and  that  all  the  other  orbs  of  space  must,  in  like 
manner,  have  obtained  their  proportion,  I  take  the  earth's 
mass,  and  its  known  quantity  of  atmospheric  envelope  as 
units,  and  calculating,  by  the  simple  rule  I  have  laid  down  in 
opposition  to  Wollaston's,  I  find  that  the  total  weight  of  the 
sun's  atmosphere  should  be  at  least  117,681,623  times  that  of 
the  earth's,  and  the  pressure  at  its  base  equal,  at  least,  to 
15,233  atmospheres.  What  must  be  the  results  of  such  an 
atmospheric  -accumulation  ? 

The  experiment  of  compressing  air  in  the  condensing 
syringe,  and  thereby  lighting  a  piece  of  Getman  tinder,  is 
familiar  to  all  who  have  studied  even  the  rudiments  of  physical 
science.  Taking  the  formula)  of  Leslie  and  Dalton,  and  apply- 
ing them  to  the  solar  pressure  of  15,233  atmospheres,  we 
arrive,  according  to  Leslie,  at  the  inconceivable  temperature  of 
380,832°  0.,  or  685,529°  F.,  as  that  due  to  this  amount  of 
compression,  or,  according  ±o  Dalton,  at  761,665°  F.  What 
will  be  the  effects  of  such  a  degree  of  heat  upon  materials  simi- 
lar to  those  of  which  our  earth  is  composed  ? 

Let  us  first  take  the  case  of  water,  which,  for  reasons  I  have 
stated,  should  be  regarded  as  atmospheric,  or  universally 
diffused  matter. 

This  brings  us  to  a  subject  of  the  highest  and  widest  philo- 
sophical and  practical  importance.  I  refer  to  the  antagonism 
between  the  force  of  heat  and  that  of  chemical  combination, 
to  which  the  French  chemists  have  given  the  name  "  dissocia- 


TI1E    FUEL   OF  THE   SUK.  7  • 

tion."  Having  myself  been  unable  to  find  any  satisfactory 
English  account  of  this  subject  at  a  time  when  it  had  already 
been  well  treated  by  French  and  German  authors,  in  the  form 
of  published  lectures  and  cyclopaedia  articles,  I  assume  that 
others  may  have  encountered  a  similar  difficulty,  and  therefore 
Iwell  rather  more  fully  upon  this  part  of  my  present  sum- 
.nary. 

It  appears  that  all  chemical  compounds  may  be  decomposed 
by  heat,  and  that,  at  a  given  pressure,  there  is  a  definite  and 
special  temperature  at  which  the  decomposition  of  each  com- 
pound is  effected.  For  the  absolute  and  final  establishment  of 
the  universality  of  this  law  further  investigations  are  necessary, 
actual  investigations  having  established  it  as  far  as  they  have 
gone,  but  these  have  not  been  exhaustive. 

There  appears  to  be  a  remarkable  analogy  between  disso- 
ciation and  evaporation.  When  a  liquid  is  vaporized,  a  cer- 
tain amount  of  heat  is  "  rendered  latent,"  and  this  quantity 
varies  with  the  liquid  and  with  the  pressure,  but  is  definite  and 
invariable  for  each  liquid  at  a  given  pressure.  In  like  manner, 
when  a  compound  is  dissociated,  a  certain  amount  of  heat  is 
"  rendered  latent"  or  conveited  into  dissociating  force,  and 
this  varies  with  each  compound  and  with  the  pressure,  but  is 
definite  and  invariable  for  each  compound  at  a  given  pressure. 
Further,  when  condensation  occurs,  an  amount  of  heat  is  evolv- 
ed, as  temperature,  exactly  equal  to  that  which  was  rendered 
latent  in  the  evaporation  of  the  same  substance  under  the  same 
pressure  ;  and,  in  like  manner,  when  chemical  recombination 
of  dissociated  elements  occurs,  an  amount  of  heat  is  evolved, 
as  temperature,  exactly  equal  to  that  which  disappeared  when 
the  compound  was  dissociated  by  heat  alone  under  the  same 
pressure. 

According  to  the  recently  adopted  figures  of  M.  Deville,  the 
temperature  at  which  the  vapor  of  water  becomes  dissociated 
under  ordinary  atmospheric  pressure  is  2800°  C. ,  and  the 
quantity  of  heat  which  disappears,  as  temperature,  in  the 
course  of  dissociation  is  2153  calories — i.e.  sufficient  to  raise 
2153  times  its  own  weight  of  liquid  water  1°  C. ;  but,  as  the 
specific  heat  of  aqueous  vapor  is  to  that  of  liquid  water  as  0*475 
to  1,  the  latent  heat  expressed  in  the  temperature  it  would 
have  given  to  aqueous  vapor  is  =  4532°  C.,  or  8158°  F. 

In  order  to  render  the  analogy  between  the  ebullition  and 
dissociation  of  water  more  evident  and  intelligible,  I  will  state 
it  as  follows  : 


78  SCIENCE   IX   SHORT   CHAPTERS. 

To  commence  the  ebullition  of  To  commence  the  dissociation  of 

water  under  ordinary  pressure,  aqueous  vapor  under  ordinary 

a  temperature  of  100°  C.,  or  pressures,  a  temperature  of 

212°  F.,  must  be  attained.  2800°  C.,  or  5072  F.,  must  be 

attained. 

To  complete  the  ebullition  of  a  To  complete  the  dissociation  of 

.given  quantity  of  water,  an  a  given  quantity  of  aqueous 

amount  of  heat  must  be  ap-  vapor,  an  amount  of  heat  must 

plied,  sufficient  to  have  raised  be  applied  sufficient  to  have 

the  water  537°  C.,  or  968°  F.,  raised  the  vapor  4532°  C.,  or 

above  its  boiling-point,  had  it  8158°  F.,  above  its  dissociation- 

not  evaporated.  point  had  it  not  decomposed. 

In  order  that  a  given  quantity  of  In  order  that  a  given  quantity  of 
vapor  of  water  shall  condense,  the  elements  of  water  may  coin- 
it  must  give  off  sufficient  heat  bine,  they  must  give  off  suffi- 
to  raise  its  own  weight  of  water  cient  heat  to  raise  their  own 
537°  C.,  or  968°  F.  weight  of  aqueous  vapor  4532° 

C.,  or  8158°  F. 

I  have  expressed  these  generalizations  and  analogies  rather 
more  definitely  than  they  have  been  hitherto  stated,  but  those 
who  are  acquainted  with  the  researches  of  Devi  lie,  Cailletet, 
Bansen,  etc.  will  perceive  that  I  am  justified  in  doing  so.* 

With  the  general  laws  of  the  dissociation  of  water  thus 
before  us,  we  may  follow  out  the  necessary  action  of  the  above- 
stated  pressure  and  consequent  evolution  of  heat  in  the  lower 
regions  of  the  solar  atmosphere  upon  the  large  proportion  of 
aqueous  vapor  which  I  have  shown  that  it  should  contain. 

It  is  evident  that  the  first  result  will  be  separation  of  this 
water  into  its  elements,  accompanied  with  a  loss  of  temperature 
corresponding  to  the  latent  heat  of  dissociation.  We  may 
assume  that  in  the  lower  regions  of  the  solar  atmosphere  the 
free  heat  evolved  by  mechanical  compression  will  be  more  than 
sufficient  to  dissociate  the  whole  of  the  aqueous  vapor,  and 
thus  the  dissociated  gases  will  be  left  at  a  higher  temperature 
than  was  necessary  to  effect  their  dissociation.  Their  condi- 
tion will  thus  be  analogous  to  that  of  superheated  steam,  they 
will  have  to  give  off  some  heat  before  they  can  begin  to  com- 
bine.•}• 

*  Since  the  above  was  written,  these  analogies  have  been  generally 
accepted. 

f  Since  the  publication  of  "  The  Fuel  of  the  Sun,"  Mr.  Norman  Lock  - 
yer  has  adopted  this  view  of  solar  dissociation,  and  has  gone  so  far  as  to 
suppose  that  it  splits  metals  and  other  substances  regarded  by  modern 
chemists  as  simple  elements  into  more  elementary  and  simple  con- 
stituents. He  assumes  that  the  temperature  of  the  solar  atmosphere, 
growing  higher  at  increasing  depths,  becomes  somewhere  capable  of 


THE   FUEL   OF   THE   SUX.  79 

There  will,  however,  be  somewhere  an  elevation  at  which 
the  heat  evolved  by  the  joint  compression  of  the  elementary 
and  combined  gases  will  be  just  sufficient  to  dissociate  the 
latter,  and  here  will  be  the  meeting  surface  of  the  combined 
and  the  uncombined  constituents  of  water.  There  will  be  a 
sphere  containing  uncombined  oxygen  and  hydrogen  sur- 
rounded by  an  atmospheric  envelope  containing  large  quanti- 
ties of  aqueous  vapor,  and  the  temperature  at  this  limiting 
surface  will  be  equal  to  that  of  the  oxyhydrogen  flame  under  a 
corresponding  pressure. 

What  will  occur  under  these  conditions  ?  Will  the  "  detonat- 
ing gases"  bchaVe  as  in  the  laboratory  ?  Obviously  not,  as  a 
glance  at  the  third  of  the  above  parallel  propositions  will  show. 
The  dissociated  gases  cannot  combine  without  giving  off  their 
4532°  of  latent  heat  as  actual  temperature.  This  can  only  be 
effected  by  communication  with  matter  which  is  cooler  than 
itself. 

If  a  bubble  of  steam  is  surrounded  by  water  maintained  at 
the  boiling  temperature,  it  will  not  condense  at  all,  because 
any  effort  of  condensation  would  be  accompanied  with  an 
evolution  of  heat  exactly  sufficient  to  evaporate  its  own  result. 
If,  however,  the  surrounding  water  is  slowly  radiating,  or 
otherwise  losing  its  heat,  the  inclosed  bubble  of  steam  will 
condense  proportionately,  by  giving  off  to  its  envelope  an 
amount  of  its  latent  heat  just  sufficient  to  maintain  the  water 
at  the  boiling-point. 

For  further  illustration,  let  us  conceive  the  case  of  a  certain 
quantity  of  tliG  elements  of  water  heated  exactly  to  the  tem- 
perature of  dissociation,  and  confined  in  a  vessel  the  sides  of 
which  are  maintained  externally  at  precisely  the  same  tempera- 
ture as  the  gases  within,  so  that  no  heat  can  be  added  or  taken 
away  from  them.  No  sensible  amount  of  combination  can. 
take  place,  as  the  first  infinitesimal  effort  of  combustion,  or 
combination,  would  set  free  just  the  amount  of  heat  require' 
to  decompose  its  own  result.  Let  us  now  suppose  a  modific. 

doing  far  greater  dissociation  work  than  that  which  separates  the 
hydrogen  of  the  prominences  revealed  by  the  spectroscope.  In. 
putting  forth  this  "working  hypothesis"  he  seems  to  have  lost  sight 
of  the  fact  clearly  proved  by  Deville's  experiments,  that  the  tem- 
perature of  dissociation  rises  with  the  pressure  to  which  the  com- 
pound is  subjected,  and  thus  that  within  the  bowels  of  the  sun  the 
metals  will  be  far  less  dissociable  than  they  are  on  the  surface  of  our 
earth. 


80  SCIKXCE    IX   SHOUT   CHAPTERS. 

tion  of  these  conditions — -viz.  that  the  vessel  containing  the 
dissociated  gases,  at  the  temperature  of  dissociation,  shall  be 
surrounded  with  bodies  cooler  than  itself — i.e.  capable  of 
receiving  more  heat  from  it  than  they  radiate  toward  it  ;  there 
would  then  take  place  just  so  much  combustion  as  would  set 
free  the  amount  of  heat  required  to  maintain  the  temperature 
of  the  vessel  at  the  dissociation-point  ;  or,  in  other  words, 
combustion  would  go  on  to  the  extent  of  setting  free  just  so 
much  heat  as  the  gaseous  mass  was  capable  of  radiating,  or 
otherwise  transmitting  to  surrounding  bodies  ;  and  this  amount 
of  combustion  would  continue  till  all  the  gases  lu.d  combined. 

We  have  only  to  give  this  hypothetical  vessel  a  spherical 
form  and  an  internal  diameter  of  853,380  miles — to  construct 
its  enveloping  sides  of  a  thick  shell  of  aqueous  vapor,  etc.,  and 
then,  by  placing  in  the  midst  of  the  contained  dissociated  gases 
a  nucleus  of  some  kind,  we  are  hypothetically  supplied  with 
the  main  conditions  which  I  suppose  to  exist  in  the  sun. 

A  little  reflection  upon  the  application  of  the  above- stated 
laws  to  these  conditions  will  show  that  the  stupendous  ocean 
of  explosive  gases  would  constitute  an  enormous  stock  of  fuel 
capable,  by  its  combustion,  of  setting  free  exactly  the  same 
quantity  of  heat  as  had  previously  been  con v cited  into  decom- 
posing or  separating  force  ;  the  amount  of  combustion  would 
always  be  limited  by  the  possible  amount  of  radiation,  and  the 
radiation  would  again  be  limited  by  the  resisting  envelope  of 
aqueous  vapor  produced  by  this  combustion. 

If  these  conditions  existed  in  a  perfectly  calm  and  undisturb- 
ed solar  atmosphere,  there  would  be  a  continually  increasing 
external  envelope  of  aqueous  vapor,  and  a  continually  diminish- 
ing inner  atmosphere  of  combustible  gases  ;  there  would  be  a 
gradual  diminution  of  the  amount  of  solar  radiation,  and  a  slow 
and  perpetually  retarding  progress  toward  solar  extinction. 

It  should  be  noted  that,  according  to  this  explanation,  the 
supply  of  heat  is  originally  derived  from  atmospheric  condensa- 
tion due  to  gravitation,  that  the  storage  of  surplus  heat  is 
effected  by  dissociation,  and  its  evolution  mainly  by  recombina- 
tion or  combustion. 

The  great  difficulty,  that  of  the  perpetual  renewal  of  the 
solar  fuel,  still  remains  unsolved  ;  the  fact  that  during  the 
millions  of  years  of  geological  history  we  find  no  indications  of 
any  declining  average  of  solar  energy  is  so  far  still  unexplained 
by  this,  as  by  every  other,  attempt  to  account  for  the  origin 
of  solar  and  stellar  linht  and  heat. 


THE   FUEL   OF   THE   SUX.  81 

In  his  inaugural  address  to  the  British  Association  Meeting 
of  1866,  Mr.  Grove  put  the  following  very  suggestive  ques- 
tion :  "  Our  sun,  our  earth,  and  planets  arc  constantly  radiat- 
ing heat  into  space  ;  so,  in  all  probability,  arc  the  other. suns, 
the  stars,  and  their  attendant  planets.  What  becomes  of  the 
heat  thus  radiated  into  space  ?  If  the  universe  has  no  limit — 
and  it  is  difficult  to  conceive  one — there  is  a  constant  evolution 
of  heat  and  light  ;  and  yet  more  is  given  oif  than  is  received 
by  each  cosmical  body,  for  otherwise  night  would  be  as  light 
and  as  warm  as  day.  What  becomes  of  the  enormous  force 
thus  apparently  non-recurrent  in  the  same  form  ?" 

This  is  a  grand  question,  a  philosophical  thought  worthy  of 
the  author  of  ' '  The  Correlation  of  Physical  Forces. ' 7  Most 
philosophical  thinkers  will,  I  believe,  agree  with  me  in  con- 
cluding that  a  sound  reply  to  it  will  solve  the  great  mystery  of 
the  everlasting  radiations  of  our  sun  and  all  the  other  suns  of 
the  universe.  So  long  as  we  regard  these  suns  as  the  sources 
of  continually  expanded  forces  of  light  and  heat,  their  ever- 
lasting and  unabated  renewal  becomes  a  mystery  utterly 
inscrutable  to  the  human  intellect,  since  the  creation  of  new 
force,  or  any  addition  to  the  total  forces  of  the  universe,  is  as 
inconceivable  to  us  as  any  addition  to  the  total  matter  of  the 
universe.  The  great  solar  question  assumes  a  far  more  hope- 
ful shape  when  we  admit  that  all  the  forces  of  past  radiations 
are  somewhere  diffused  in  space,  and  we  ask  whether  a  sun 
contains  any  mechanism  by  which  it  may  collect  and  concen- 
trate this  diffused  force,  and  thus  perpetually  gather  from 
surrounding  suns  as  much  as  it  radiates  toward  them. 

The  next  part  of  my  work  is  an  attempt  to  show  that  such  a 
mechanism  does  exist  in  our  solar  system,  and  to  explain  its 
action. 

We  know  that  if  atmospheric  air  is  compressed  it  becomes 
heated,  that  if  this  heat  is  allowed  to  radiate  and  the  air  is 
again  expanded  to  its  original  dimensions,  it  will  be  cooled 
below  its  original  temperature  to  an  extent  precisely  equal  to 
the  heat  which  it  gave  out  when  compressed.  On  this  princi- 
ple I. endeavor  to  explain  the  everlasting  maintenance  of  the 
solar  and  stellar  radiations. 

The  sun  is  attended  by  his  train  of  planets  whose  orbital 
motion  he  controls,-  but  they  in  return  react  upon  him  as  the 
moon  does  upon  the  earth.  If  this  reaction  were  regular,  like 
that  of  the  moon  upon  the  earth,  a  regular  atmospheric  tide 
would  result  ;  but  the  great  irregularity  of  the  dimensions,  dis- 


82  SCIENCE   IN   SHOUT   CHAPTERS. 

tances,  and  velocities  of  the  planets  produces  a  result  equiva- 
lent to  a  number  of  clashing  irregular  tides  in  the  solar  atmos- 
phere ;  or,  otherwise  stated,  the  centre  of  motion  and  centre 
of  gravity  of  the  whole  system  will  be  perpetually  varying  with 
the  varying  relative  positions  of  the  planets,  and  thus  the  solar 
nucleus  and  solar  atmosphere  will  be  subject  to  irregularities  of 
motion,  which,  though  very  small  relatively  to  the  enormous 
magnitude  of  the  sun,  must  be  sufficient  to  produce  mighty 
vortices,  and  thus  effect  a  continual  commingling  between  the 
outer  and  inner  atmospheric  strata. 

It  must  be  remembered  that,  according  to  the  preceding,  the 
inner  or  lower  strata  of  the  solar  atmosphere  should  consist  of 
our  ordinary  atmospheric  mixture  of  oxygen  and  nitrogen,  and 
the  dissociated  elements  of  water  and  carbonic  acid,  besides 
some  of  the  more  volatile  elements  of  the  solar  nucleus.  Out- 
side of  this  there  should  be  a  boundary  limit  where  the  disso- 
ciated gases  are  combining  as  rapidly  as  their  latent  heat  can 
be  evolved  by  radiation  ;  this  will  form  a  shell  or  sphere  of 
flame — the  photosphere — and  above  or  beyond  this  will  be  the 
sphere  of  vapors  resulting  from  this  combustion,  which,  by 
their  resistance  to  radiation,  will  limit  the  evolution  of  heat  and 
consequent  combustion. 

Now  the  vortices  above  referred  to  will  break  through  the 
shell  of  combustion,  and  drag  down  more  or  less  of  the  outer 
vapor  into  the  lower  and  hotter  regions  of  dissociated  gases. 

As  there  can  be  no  action  without  equal  and  contrary  reac- 
tion, there  can  be  no  vortices,  either  in  the  solar  atmosphere  or 
a  terrestrial  stream,  without  corresponding  upheavals.  These 
upheavals  will  eject  the  lower  dissociated  gases  more  or  less 
completely  through  the  vaporous  jacket  which  restrains  their 
normal  radiations,  and,  thus  liberated,  they  will  rush  into 
combination  with  an  explosive  energy  comparable  to  that 
which  they  display  in  our  laboratories  ;  not,  however,  with  an 
instantaneous  flash,  but  with  a  continuous  rocket-like  combus- 
tion, the  rapidity  of  which  will  be  determined  by  the  possibil- 
ity of  radiation.  The  heat  evolved  by  this  combustion,  acting 
simultaneously  with  the  diminution  of  pressure,  will  effect  a 
continually  augmenting  expansion  of  these  upheaved  gases,  and 
as  the  rapidity  of  combustion  will  be  accelerated  in  proportion 
to  elevation  above  the  restraining  vapors,  an  outspreading  far 
in  excess  of  that  which  would  be  due  to  the  original  upheaving 
force  is  to  be  expected. 

The  reader  who  is  acquainted  with  the  phenomena  of  the 


THE   FUEL  OF   THE   SUX.  83 

solar  prominences  will  at  once  perceive  how  all  these  expecta- 
tions are  fulfilled  by  actual  observations,  especially  by  the  more 
recent  observations  of  Zollner,  Secchi,  etc.,  which  exhibit  the 
typical  solar  prominence  as  a  stem  or  jet  rushing  upward 
through  some  restraining  medium,  and  then  expanding  into  a 
cloudlike  or  palm-tree  form  after  escaping  from  this  restraint. 
I  need  scarcely  add  that  the  clashing  tide  waves  are  thefaculce, 
and  the  vortices  the  sun-spots. 

My  present  business,  however,  is  to  show  how  these  vortices 
and  eruptions — this  down-rush  in  one  part  of  the  solar  atmos- 
phere and  up-rush  in  another — contribute  to  the  permanent 
maintenance  of  the  solar  light  and  heat.  It  must  be  under- 
stood that  these  outbursts  are  only  visible  to  us  as  luminous 
prominences  during  the  period  of  their  explosive  outburst, 
and  while  still  subject  to  great  expansive  tension.  Long  after 
they  have  ceased  to  be  visible  to  us  their  expansion  must  con- 
tinue, until  they  finally  and  fully  mingle  with  the  medium  into 
which  they  are  flung,  and  attain  a  corresponding  degree  of 
rarefaction.  This  must  occur  at  tens  and  hundreds  of  thou- 
sands of  miles  above  the  photosophere,  according  to  the  magni- 
tude of  the  ejection.  The  spectroscopic  researches  of  Frank- 
land  and  Lockyer  having  shown  that  the  atmospheric  pressure 
at  about  the  outer  surface  of  the  photosphere  does  not  far 
exceed  that  of  our  atmosphere,  I  may  safely  regard  all  the 
upper  portion  of  these  solar  ejections  as  having  left  the  solar 
atmosphere  proper,  and  become  commingled  with  the  general 
interstellar  medium. 

If  the  sun  were  stationary,  or  merely  rotating,  in  the  midst 
of  this  universal  atmosphere,  the  same  material  that  is  ejected 
to-day  would  in  the  course  of  time  return,  and  be  whirled  into 
the  great  sun-spot  eddies  ;  but  such  is  not  the  case  ;  the  sun 
is  driving  through  the  ether  with  a  velocity  of  about  450,000 
miles  per  twenty-four  hours. 

What  must  be  the  consequence  of  this  motion  ?  The  sun 
will  carry  its  o\vn  special  atmospheric  matter  with  it  ;  but  it 
cannot  thus  carry  the  whole  of  the  interstellar  medium.  There 
must  be  a  limit,  graduated  no  doubt,  but  still  a  practical  limit, 
at  which  its  own  atmosphere  will  leave  behind,  or  pass  through, 
the  general  atmospheric  matter.  There  must  be  a  heaping  or 
condensation  of  this  matter,  in  the  front,  a  rarefaction  or  wake 
in  the  rear,  and  a  continuous  flow  of  newly  encountered  atmos- 
phere around  the  boundaries  in  the  opposite  direction  to  that 
of  the  sun's  motion.  The  result  of  this  must  be  that  a  great 


84  SCIENCE   IN   SHORT   CHAPTERS. 

portion  of  the  ejected  atmospheric  matter  of  the  prominences 
will  be  swept  permanently  to  the  rear,  and  its  place  supplied 
by  the  material  occupying  the  space  into  which  the  sun  is 
advancing.  We  are  thus  presented  with  a  mighty  machinery 
of  solar  respiration  ;  some  of  this  newly  arriving  atmospheric 
•natter  must  be  stirred  into  the  vortices,  its  quantity  being 
xactly  equivalent  to  that  of  the  old  material  expired  by  the 
explosive  eruptions,  and  left  in  the  rear. 

Now,  the  new  atmospheric  matter  which  is  thus  encountered 
and  inspired  is  the  recipient  of  the  everlasting  radiations 
whose  destination  is  the  subject  of  Mr.  Grove's  inquiry  ;  and 
these,  when  thus  encountered  and  compressed,  will  of  neces- 
sity evolve  more  or  less  of  the  heat  which,  through  millions  of 
millions  of  centuries,  they  have  been  gradually  absorbing  ; 
while,  on  the  other  hand,  the  expired  or  ejected  matter  of  the 
gaseous  eruptions  will,  like  the  artificially  compressed  air  above 
referred  to,  have  lost  all  the  heat  which  during  its  solar  exist- 
ence it  had  by  compression,  dissociation,  and  recombination 
contributed  to  the  solar  radiations.  Therefore,  when  again 
fully  expanded,  it  will  be  cooler  than  the  general  medium  from 
which  it  was  originally  inspired  by  the  advancing  sun. 

The  daily  supply  of  fresh  atmospheric  fuel  will  be  a  cylinder 
of  ether  of  the  same  diameter  as  the  sun,  and  450,000  miles 
in  length  !  I  have  calculated  the  weight  of  this  cylinder  of 
ether  on  the  assumption  (which  of  course  is  purely  arbitrary) 
that  the  density  of  the  interstellar  medium  is  one  ten-thou- 
sandth part  of  that  of  our  atmosphere.  It  amounts  to 
14,313,915,000,000,000,000  tons,  affording  a  supply  of  165 
millions  of  millions  of  tons  per  second  ;  or,  if  we  assume  the 
interstellar  medium  to  have  a  density  of  only  one  millionth  of 
that  of  our  atmosphere,  the  supply  would  be  rather  more  than 
one  and  a  half  millions  of  millions  of  tons  per  second.  The 
proportion  of  this  which  is  effective  in  the  manner  above 
stated  is  that  which  becomes  stirred  into  the  lower  regions  of 
the  sun  in  exchange  for  the  ejected  matter  of  the  prominences. 

I  will  not  here  dwell  upon  the  bombardment  hypothesis, 
beyond  observing  that  my  explanation  of  solar  phenomena  sup- 
plies a  continuous  bombardment  of  the  above  stated  magnitude 
without  adding  anything  to  the  magnitude  of  the  sun. 

So  far,  then,  I  answer  Mr.  Grove's  question,  by  showing  that 
the  heat  radiated  into  space  by  each  of  the  solid  orbs  that  people 
its  profoundities,  is  received  by  the  universal  atmospheric 
medium  ;  is  gathered  again  by  the  breathing  of  wandering 


THE   FUEL   OF  THE   SUN.  85 

suns,  who  inspire  as  they  advance  the  breath  of  universal  heat 
and  light  and  life  ;  then,  by  impact,  compression,  and  radia- 
tion, they  concentrate  and  redistribute  its  vitalizing  power  ; 
and  after  its  work  is  done,  expire  it  in  the  broad  wake  of  their 
retreat,  leaving  a  track  of  cool  exhausted  ether — the  ash-pits 
of  the  solar  furnaces — to  reabsorb  the  general  radiations,  and 
thus  maintain  the  eternal  round  of  life. 

But  ere  this  a  great  difficulty  has  probably  presented  itself 
to  the  mind  of  the  reader.  He  will  refer  to  the  calculations 
that  have  been  made  in  order  to  determine  the  actual  tempera- 
ture of  the  solar  surface  and  the  intensity  of  its  luminosity. 
Both  of  these  are  vastly  in  excess  of  those  obtained  in  our 
laboratory  experiments  by  the  combustion  of  the  elements  of 
water.  Even  taking  into  consideration  the  dissociated  carbonic 
acid  whose  elements  should  be  burning  in  the  photosphere 
with  those  of  water,  and  adding  to  these  the  volatile  metals  of 
the  solar  nucleus  whose  dissociated  vapors  must,  under  the  cir- 
cumstances stated,  be  commingled  with  those  of  the  solar 
atmosphere,  and  therefore  contribute  to  the  luminosity  by 
their  combustion,  still  by  burning  here  on  the  earth  a  jet  of 
such  mixed  gases  and  vapors  we  should  not  obtain  any 
approach  to  either  the  luminosity  or  the  temperature  which  is 
usually  attributed  to  the  sun. 

I  have  made  a  few  very  simple  experiments,  the  results  of 
which  remove  these  difficulties.  They  were  conducted  with 
the  assistance  of  Mr.  Jonathan  Wilkinson,  the  official  gas 
examiner  to  the  Sheffield  Corporation,  using  his  photometric 
and  gas-measuring  apparatus.  We  first  determined  the 
amount  of  light  radiated  by  a  single  fish-tail  gas-burner  consum- 
ing a  measured  quantity  of  gas  per  hour.  We  found  when 
another  was  placed  behind  this,  so  that  all  the  light  of  the 
second  had  to  pass  through  the  first,  that  the  light  of  the  two 
(measured  by  the  illuminating  intensity  of  their  radiations 
upon  a  screen  just  as  the  solar  luminosity  has  been  measured) 
was  just  double  that  of  -one  flame,  three  flames  (still  presenting 
to  the  photometric  screen  only  the  smface  of  one)  gave  it 
three  times  the  amount  of  illumination,  and  so  on  with  any 
number  of  flames  we  were  able  to  test.  Mr.  Wilkinson  has 
since  arranged  100  flames  on  the  same  principle — i.e.  so  that 
the  99  hinder  flames  shall  all  radiate  through  the  one  presented 
to  the  screen,  thus  affording  the  same  surface  as  a  single  flame, 
but  having  100  times  its  thickness  or  depth,  and  he  finds 
that  the  law  indicated  by  our  first  experiments  is  fully  verified  ; 


80  SCIENCE   IN    SHORT   CHAPTERS. 

that  the  100  flames  thus  arranged  illuminate  the  screen  100 
times  as  intensely  as  the  single  flame.  Other  modifications  of 
these  experiments,  described  in  Chapter  7  of  "  The  Fuel  of  the 
Sun,"  establish  the  principle  that  a  common  hydrocarbon  gas 
flame  is  transparent  to  its  own  radiations,  or,  in  other  words, 
that  the  amount  of  light  radiated  from  such  a  flame,  and  its 
apparent  intensity  of  luminosity,  is  proportionate  to  its  thick- 
ness ;  therefore  the  luminosity  of  the  sun  may  be  produced  by 
a  photosphere  having  no  greater  intrinsic  brilliancy  than  the 
flame  of  a  tallow  candle,  provided  the  flame  is  of  sufficient 
depth  or  thickness.  I  see  good  reasons  for  inferring  that 
its  intrinsic  brilliancy  is  less  than  that  of  a  candle — somewhere 
between  that  and  a  Bunsen's  burner. 

A  similar  series  of  experiments  upon  the  radiation  of  the 
heat  of  flames  through  each  other,  indicated  similar  results  ; 
but  my  apparatus  for  these  experiments  was  not  so  delicate  and 
reliable  as  in  the  experiments  on  light,  and,  therefore,  I 
cannot  so  decidedly  affirm  the  absolute  diathermancy  of  flame 
to  its  own  radiations.  Within  the  limits  of  error  of  these 
experiments,  I  found  that  with  the  same  radiant  surface 
presented  to  the  thermometer,  every  addition  to  the  thick- 
ness of  the  flame  produced  a  proportionate  increase  of  radia- 
tion. 

This  important  law,  though  hitherto  unnoticed  by  philoso- 
phers, is  practically  understood  and  acted  upon  by  workmen 
who  are  engaged  in  furnace  operations.  Present  space  will 
not  permit  me  to  illustrate  this  by  examples,  but  in  passing  I 
may  mention  the  "  mill  furnaces,"  where  armor  plates  and 
other  large  masses  of  iron  are  raised  to  a  welding  temperature 
by  radiant  heat,  and  the  ordinary  puddling  furnace,  where  iron 
is  melted  by  radiant  heat.  In  both  of  these,  special  arrange- 
ments are  made  to  obtain  a  "  body"  or  thickness  of  radiant 
flame,  while  intensity  of  combustion  is  neglected  and  even 
carefully  avoided. 

According  to  this  there  are  two  factors  engaged  in  produc- 
ing the  radiant  effect  from  a  given  surface,  intensity  and  quan- 
tity i.e. — brilliancy  and  thickness  in  the  case  of  light,  and  tem- 
perature and  thickness  in  the  case  of  heat.  In  the  Bude  light,  for 
example,  consisting  of  concentric  rings  of  coal  gas,  we  have 
small  intensity  with  great  quantity,  in  the  lime  light  we  have  a 
mere  surface  of  great  brilliancy,  but  no  thickness.  If  I  am 
right,  the  surface  of  the  moon  may  be  brighter  than  the 
luminous  surface  of  the  sun,  the  peculiarities  of  moonlight 


THE   FUEL   OF   THE   SUST.  8? 

depending  upon  intensity,  those  of  sunlight  upon  quantity  of 
light. 

The  flame  that  roars  from  the  mouth  of  a  Bessemer  convert- 
er has  but  small  intrinsic  brilliancy,  far  less  than  that  of  an 
ordinary  gas  name,  a*  may  be  seen  by  observing  the  thin  waifs 
that  sometimes  project  beyond  the  body  of  the  flame.  Never- 
theless, its  radiations  are  so  effective  that  it  is  a  painfully  daz- 
zling object  even  in  the  midst  of  sunny  daylight  ;  but  then  we 
have  here  not  a  hollow  flame  fed  only  by  outside  oxygen,  but 
a  solid  body  of  flame  several  feet  in  thickness.  Even  the  pallid 
carbonic  acid  flame  which  accompanies  the  pouring  of  the 
spiegeleisen  has  marvellous  illuminating  po\ver. 

The  reader  will  now  be  able  to  understand  my  explanation 
of  the  sun  spots,  of  their  nucleus,  umbra,  and  penumbra. 
From  what  I  have  stated  respecting  the  planetary  disturbances 
of  the  solar  rotation,  the  photosphere  should  present  all  the 
appearances  due  to  the  movements  of  a  fiery  ocean,  raging  and 
seething  in  the  maddest  conceivable  fury  of  perpetual  tempest. 
If  the  surface  of  a  river  flowing  peacefully  between  its  banks  is 
perforated  with  conical  eddies  whenever  it  meets  with  a  pro- 
jecting rock  or  obstacle,  or  other  agency  which  disturbs  the 
regularity  of  its  course,  what  must  be  the  magnitude  of  the 
eddies  in  this  02eau  of  flame  and  heated  gases,  wli3n  stirred  to 
the  lowest  depths  of  its  vast  profundity  by  the  irregular  reel- 
ing of  the  solar  nucleus  within  ?  Obviously,  nothing  less  than 
the  sun-spots  ;  those  mighty  maelstroms  into  which  a  world 
might  be  dropped  like  a  pea  into  an  egg-cup. 

When  the  photosphere  or  shell  of  combining  gases  is  thus 
ripped  open,  the  telescopic  observer  looks  down  the  vortex, 
which,  if  deep  enough,  reveals  to  him  the  inner  region  of 
dissociated  gases  and  vapors.  But  these  have  the  opposite 
property  to  that  which  I  have  shown  to.  belong  to  flame  ;  they 
are  opaque  to  their  own  special  radiations,  while  the  flame  is 
transparent  to  the  light  of  the  inner  portions  of  itself.  Thus, 
the  dissociated  interior  of  the  solar  envelope,  though  abso- 
lutely white-hot,  will  be  comparatively  dark  (direct  experiment 
h  is  proved  that  the  darkness  of  the  spots  is  only  relative). 

The  sides  of  the  vortex  funnel  will  consist  of  a  mixture  of 
dissociated  gases,  flaming  gases,  and  combined  gases,  and  will 
thus  present  various  thicknesses  of  flame,  and  thereby  display 
the  various  shades  of  the  penumbra.  Space  will  not  permit  me 
here  to  follow  up  the  details  of  this  subject,  as  I  have  done  in 
the  original  work,  where  it  is  shown  that  if  the  telescope  had 


88  SCIENCE    IX    SHOUT    CHAPTERS. 

not  yet  been  invented,  all  the  telescopic  details  of  spot 
phenomena  might  have  been  described  a  j.riwi  as  necessary 
consequences  of  the  constitution  I  have  above  ascribed  to  the 
sun. 

Not  merely  the  great  spot  phenomena,  but  all  the  minor 
irregularities  of  the  photosphere  follow  with  similarly  demon- 
strable necessity.  Thus  the  many  interfering  solar  tides  mus  j 
throw  up  great  waves,  literally  mountainous  in  their  magni- 
tude, the  summits  and  ridges  of  which,  being  raised  into  higher 
regions  of  the  absorbing  vaporous  atmosphere  that  envelops 
the  photosphere,  will  radiate  more  freely,  its  dissociated  matter 
will  combine  more  abundantly,  and  will  thicken  the  photo- 
sphere immediately  below  ;  this  thicker  flame  will  be  more 
luminous  than  the  normal  surface,  and  thus  produce  the 
phenomena  of  i\ie  faculce. 

Besides  these  great  ground-swells  of  the  flaming  ocean  of  the 
photosphere,  there  must  be  lesser  billows,  and  ripples  upon 
these,  and  mountain  tongues  of  flame  all  over  the  surface. 
The  crests  of  these  waves,  and  the  summits  of  these  flame-alps, 
presenting  to  the  terrestrial  observer  a  greater  depth  of  flaming 
matter,  must  be  brighter  than  the  hollows  and  valleys  between  ; 
and  their  splendor  must  be  further  increased  by  the  fact  that 
such  upper  ridges  and  summits  are  less  deeply  immersed  in  the 
outer  ocean  of  absorbing  vapors,  which  limits  the  radiation  of 
the  light  as  well  as  the  heat  of  the  photosphere.  The  effect  of 
looking  upon  the  surface  of  such  a  wild  fury  of  troubled  flame, 
with  its  confused  intermingling  of  gradations  of  luminosity, 
must  be  very  puzzling  and  difficult  to  describe  ;  and  hence  the 
"willow  leaves,"  "rice  grain>,"  "mottling,"  "granules/* 
"things,"  "flocculi,"  "bits  of  white  thread,"  "  cumuli  of 
cotton  wool,"  "excessively  minute  fragments  of  porcelain," 
"  untidy  circular  masses,"  "  ridges,"  "  waves,"  "  hill  knolls," 
etc.,  etc.,  to  which  the  luminous  ii regularities  have  been 
compared. 

At  the  time  I  wrote,  the  means  of  examination  of  the  edge 
of  the  sun  by  the  spectroscope  was  but  newly  discovered,  and 
the  results  then  published  referred  chiefly  to  the  prominences 
proper.  Since  that,  a  new  term  has  been  introduced  to  solar 
technology,  the  "  sierra,"  and  the  observations  of  the  actual 
appearances  of  this  sierra  precisely  correspond  to  my  theoretical 
description  of  the  limiting  surface  of  the  photosphere,  which 
was  written  before  I  was  acquainted  with  these  observed  facts. 
This  will  be  seen  by  reference  to  Chapter  10,  the  subject  of 


THE  FUEL   OF  THE   SUN.  89 

which  is,  u  The  Varying  Splendor  of  Different  Portions  of 
the  Photosphere."* 

But  I  must  not  linger  any  further  upon  this  part  of  the  sub- 
ject, but  proceed  to  another,  where  subsequent  discoveries 
have  strongly  confirmed  my  speculations. 

The  mean  specific  gravity  of  the  sun  is  not  quite  1-J-  times 
that  of  water.  The  vapors  of  nickel,  cobalt,  copper,  iron, 
chromium,  manganese,  titanium,  zinc,  cadmium,  aluminium, 
magnesium,  barium,  strontium,  calcium,  and  sodium  have  been 
shown  by  the  spectroscope  to  be  floating  on  the  outer  regions 
of  the  sun.  None  of  these  could  constitute  the  body  of  the 
sun  in  a  solid  or  liquid  state,  and  be  subjected  to  the  enormous 
pressure  which  such  a  mass  must  exert  upon  itself  without 
raising  the  mean  specific  gravity  vastly  above  this  ;  nor  is  there 
any  other  kind  of  matter  with  which  we  are  acquainted  which 
could  exist  within  so  large  a  mass  in  a  liquid  or  solid  state, 
and  retain  so  low  a  density. 

I  must  confess  that  my  faith  in  the  logical  acumen  of  mathe- 
maticians has  been  rudely  shaken  by  the  manner  in  which 
eminent  astronomers  have  described  the  umbra  or  nucleus  of 
the  sun-spots  as  the  solid  body  of  the  sun  seen  through  his 
luminous  atmosphere,  and  the  solid  surface  of  Jupiter  seen 
through  his  belts,  and  have  discussed  the  habitability  of 
Jupiter,  Saturn,  Uranus,  and  Neptune  always  on  the  assumption 
of  their  solidity,  while  the  specific  gravity  of  all  of  these 
renders  this  surface  solidity  a  demonstrable  physical  impossi- 
bility. 

If  the  sun  (or  either  of  these  planets)  has  a  solid  or  liquid 
nucleus,  it  must  be  a  mere  kernel  in  the  centre  of  a  huge  orb 
of  gaseous  matter,  and  though  I  have  spoken  rather  definitely 
of  the  solar  atmosphere  in  order  to  avoid  complication,  I  must 
not,  therefore,  be  understood  to  suppose  that  there  exists  in 
the  sun  any  such  definite  boundary  to  the  base  of  the  atmos- 
pheric matter  as  we  find  here  on  the  earth.  The  temperature, 
the  density,  and  all  we  know  of  the  chemistry  of  the  sun  justi- 
fy the  conclusion  that  in  its  outer  regions,  to  a  considerable 
depth  below  the  photosphere,  there  must  be  a  commingling  of 
the  atmospheric  matter  with  the  vapors  of  the  metals  whose 
existence  the  spectroscope  has  revealed.  Some  of  these  must 
be  upheaved  together  with  the  dissociated  elements  of  water. 

*  Still  more  recently  (1882)  the  magnificent  photographs  of 
Jannsen  have  displayed  further  evidence  of  the  flame-tongue  charac- 
ter of  the  mottling. 


1)0  SCIENCE    IN    SHORT   CHAPTERS. 

They  are  all  combustible,  and,  with  a  few  exceptions,  the  prod- 
ucts of  their  combustion  would  solidify  after  they  were  pro- 
jected beyond  the  photosphere.  Much  of  the  iron,  nickel, 
cobalt,  and  copper  might  pass  through  the  fiery  ordeal  of  such 
projection,  and  solidify  without  oxidation,  especially  when 
more  or  less  enveloped  in  uncombined  hydrogen. 

It  is  obvious  that,  under  these  circumstances,  there  must 
occur  a  series  of  precipitations  analogous  to  those  from  the 
aqueous  vapor  of  our  atmosphere.  These  gaseous  metals,  or 
their  oxides,  must  be  condensed  as  clouds,  rain,  snow,  and 
hail,  according  to  their  boiling  and  melting  points,  and  the 
conditions  of  their  ejection.  We  know  that  sudden  and 
violent  atmospheric  disturbance,  accompanied  with  fierce  elec- 
trical discharges,  especially  favor  the  formation  of  hailstones  in 
our  terrestrial  atmosphere.  All  such  violence  must  be  display- 
ed on  a  hugely  exaggerated  scale  in  the  solar  outbursts,  and 
therefore  the  hailstone  formation  should  preponderate,  especial- 
ly as  the  metallic  vapors  condense  more  rapidly  than  those  of 
water -on  account  of  the  much  smaller  amount  of  their  specific 
heat  and  of  the  latent  heat  of  their  vapors. 

What  will  become  of  these  volleys  of  solid  matter  thus  eject- 
ed with  the  furious  and  protracted  explosions  forming  the 
solar  prominences  ?  In  order  to  answer  this  question,  we  must 
remember  that  the  spectroscope,  as  recently  applied,  merely 
displays  the  gaseous,  chiefly  the  hydrogen,  ejections  ;  that 
these  great  gaseous  flames  bear  a  similar  relation  to  the  solid 
projectiles  that  the  flash  of  a  gun  does  to  the  grapeshot  or 
cannon-ball.  Mr.  Lockyer  says  :  "  In  one  instance  I  saw  a 
prominence  27,000  miles  high  change  enormously  in  the  space 
of  ten  minutes  ;  and,  lately,  I  have  seen  prominences  much 
higher  born  and  die  in  an  hour. "  He  has  recently  measured 
an  actual  velocity  of  120  miles  per  second  in  the  movements  of 
this  gaseous  matter  of  the  solar  eruptions,  the  initial  velocity  of 
which  must  have  been  much  greater.*  If  such  is  the  velocity 
of  the  gaseous  ejections,  what  must  be  that  of  the  solid  pro- 
jectiles, and  where  must  they  go  ? 

A  cosmical  cannonade  is  a  necessary  result  of  the  condi- 
tions I  have  sketched,  and  as  prominence-ejections  are  continu- 
ally in  progress,  there  must  be  a  continual  outpouring  from  the 
sun  of  solid  fragments,  which  must  be  flung  far  beyond  the 

*  Subsequent  observations  (1882)  by  Secchi,  Young,  and  others 
have  demonstrated  velocities  far  exceeding  this  ;  quite  sufficient  to 
project  the  solid  matter  clearly  beyond  the  sphere  of  solar  attraction. 


THE   FUEL   OF  THE   SUX.  91 

limits  of  the  gaseous  prominences.  As  the  luminosity  of  these 
glowing  particles  must  be  very  smalll  compared  with  that  of 
the  photosphere,  they  will  be  invisible  in  the  glare  of  ordinary 
sunshine  ;  but  if  our  eyes  be  protected  from  this,  they  may 
then  be  rendered  visible,  both  by  their  own  glow  and  the  solar 
light  they  are  capable  of  reflecting.  They  should  be  seen 
during  a  total  eclipse,  and  should  exhibit  radiant  streams  pro- 
ceeding irregularly  from  different  parts  of  the  sun,  but  most 
abundantly  from  the  neighborhood  of  the  spot  regions.  As 
these  spot  regions  occupy  the  intermediate  latitudes  between 
the  poles  and  the  equator  of  the  sun,  the  greatest  extensions  of 
the  outstreamings  should  be  N.  E.  and  S.  W.  and  S.  E.  and 
N.  W.,  while  to  the  N.,  S.,  E.,  and  W. — that  is,  opposite  the 
poles  and  equator  of  the  sun — there  should  be  a  lesser  exten- 
sion. The  result  of  this  must  be  an  approximation  to  a 
quadrilateral  figure,  the  diagonals  of  which  should  extend  in  a 
N.  E.  and  S.  W.,  and  a  S.  E.  aad  N.  W.  direction,  or  there- 
abouts. I  say  * '  thereabouts, "  because  the  zone  of  greatest 
activity  is  not  exactly  intermediate  between  the  poles  and  the 
equator,  but  lies  nearer  to  the  solar  equator. 

Examined  with  the  polariscope,  these  radiant  streams  should 
display  a  mixture  of  reflected  light  and  self-luminosity.  Ex- 
amined with  the  spectroscope,  a  faint  continuous  spectrum 
due  to  such  luminosity  of  solid  particles  should  be  exhibited, 
with  possibly  a  few  lines  due  to  the  small  amount  of  vapor 
which,  in  their  glowing  condition,  they  might  still  give  off. 
Besides  this,  there  should  appear  the  spectroscope  indications 
of  violent  electrical  discharges,  which  must  occur  as  a  neces- 
sary concomitant  of  the  furious  ejections  of  aqueous  vapor  and 
solid  particles.  All  these  metallic  hailstones  must  be  highly 
charged,  like  the  particles  of  vesicular  vapor  ejected  from  the 
hydro-electric  machine,  or  the  vapors  and  projectiles  of  a 
terrestrial  volcanic  eruption. 

I  need  scarcely  add  that  this  exactly  describes  the  actually 
observed  results  of  the  recent  observations  on  the  corona,  and 
that  all  the  phenomena  of  this  great  solar  mystery  are  but 
necessary  and  predicable  results  of  the  constitution  I  ascribe  to 
the  sun. 

There  is  a  method  of  manufacturing  hypotheses  which  has 
become  rather  prevalent  of  late,  especially  among  mathemati- 
cians, who  take  observed  phenomena,  and  then  arbitrarily  and 
purely  from  the  raw  material  of  their  own  imagination  con- 
struct explanatory  atoms,  media,  and  actions,  which  are  shaved 


92  SCIENCE   IX    SHORT   CHAPTERS. 

and  pared,  scraped  and  patched,  lengthened  and  shortened, 
thickened  and  narrowed,  till  they  are  made  to  fit  the  phenom- 
ena with  mathematical  accuracy.  These  Laborious  creations 
are  then  put  forth  as  philosophical  truths,  and,  afterward,  the 
accuracy  of  their  fitting  to  the  phenomena  is  quoted  as  evi- 
dence of  the  positive  reality  of  the  ethers,  atoms,  undulations, 
i gyrations,  collisions,  or  whatever  else  the  mathematician  may 
have  thus  skilfully  created  and  fitted.  It  appears  to  me  that 
such  fitness  only  proves  the  ingenuity  of  the  fitter — the  skill  of 
the  mathematician — and  that  all  such  hypotheses  belong  to  the 
poetry  of  science  ;  they  should  be  distinctly  labelled  as  prod- 
ucts of  mathematical  imagination,  and  nowise  be  confounded 
with  objective  natural  truths.  Such  products  of  the  imagina- 
tion of  the  expert  may  assist  the  imagination  of  the  student  in 
comprehending  some  phenomena,  just  as  "  Jack  Frost"  and 
"  Billy  Wind"  may  represent  certain  natural  forces  to  babies  ; 
but  if  Jack  Frost,  Billy  Wind,  electric  and  magnetic  fluids, 
ultimate  atoms,  interatomic  ethers,  nervous  fluids,  etc.  are 
allowed  to  invade  the  intellect,  and  are  accepted  as  actual  phys- 
ical existences,  they  become  very  mischievous  philosophical 
superstitions. 

I  make  this  digression  in  order  to  repudiate  any  participation 
in  this  kind  of  speculation.  Though  tk  The  Fuel  of  the  Sun" 
is  avowedly  a  very  bold  attempt  to  unravel  majestic  mysteries, 
I  have  not  sought  to  elucidate  the  known,  by  means  of  the  un- 
known, as  do  these  inventors  of  imaginary  agents,  but  have 
scrupulously  followed  the  opposite  principle.  I  have  invented 
nothing,  but  have  started  from  the  experimental  facts  of  the 
laboratory,  the  demonstrated  laws  of  physical  action,  and  have 
followed  up  step  by  step  what  I  understand  to  be  the  necessary 
consequences  of  these.  Many  years  ago  I  convinced  myself 
that  our  atmosphere  is  but  a  portion  of  universal  atmospheric 
matter  ;  that  Dr.  Wollaston  was  wrong,  and  that  the  compres- 
sion of  this  universal  atmospheric  matter  is  possibly  the  source 
of  solar  light  and  heat  ;  but  as  this  was  long  before  M.  Deville 
had  investigated  the  subject  of  dissociation  by  heat,*  I  was 
unable  to  work  out  the  problem  at  all  satisfactorily.  When  I 
subsequently  resumed  the  subject,  I  knew  nothing  about  the 
corona,  and  had  only  read  of  the  u  red  prominences"  as  possible 
lunar  appendages,  or  solar  clouds,  or  optical  illusions.  I  had 

*  My  first  memorandum  on  the  subject  is  dated  April  23,  1840,  in 
*  Register  of  Ideas,  then  commenced  in  very  early  student  days. 


THE   Fl'EL   OF   THE   SUX.  'Jo 

worked  out  tlic  necessity  of  the  gaseous  eruptions,  and  their 
action  in  effecting  an  interchange  of  solar  and  general  atmos- 
pheric matter,  as  the  means  of  maintaining  the  solar  light  and 
heat,  with  no  idea  of  proceeding  further  with  the  problem, 
when  the  announcement  that  the  prominences  were  not  merely 
unquestionable  solar  appendages,  but  were  actually  upheaved 
mountains  of  glowing  hydrogen,  suddenly  and  unexpectedly 
suggested  their  identity  with  my  required  atmospheric  up- 
heavals. It  is  true  that  their  observed  magnitude  far  exceeded 
my  theoretical  anticipations,  and  in  this  respect  I  have  made 
some  a  posteriori  adaptations,  especially  with  the  aid  of  a 
clearer  understanding  of  the  laws  of  dissociation  which  almost 
simultaneously  became  attainable. 

In  like  manner,  the  necessity  of  the  solid  ejections  present- 
ed themselves  before  I  knew  anything  of  the  recently  discovered 
details  of  the  coronal  phenomena — when  I  had  merely  read  of 
a  luminous  halo  which  had  been  seen  around  the  sun,  and, 
relying  upon  Mr.  Lockyer,  vaguely  supposed  it  to  be  an  effect 
of  atmospheric  illumination.  I  inferred  that  streams  of  solid 
particles  must  be  pouring  from  the  sun,  and  showering  back 
again,  but  had  no  idea  that  such  streams  and  showers  were 
actually  visible  until  I  was  rather  startled  on  learning  that  the 
corona,  instead  of  being,  as  I  had  loosely  supposed,  a  mere 
uniform  filmy  halo,  had  been  described  by  Mr.  De  la  Rue,  in 
his  Bakerian  Lecture  on  the  Eclipse  of  1860,  as  "  softening  off 
with  very  irregular  outline,  and  sending  off  some  long  streams," 
etc.  I  was  then  living  on  the  sides  of  a  Welsh  mountain  far 
away  from  public  libraries,  and  being  no  astronomer,  my  own 
books  kept  me  better  acquainted  with  the  current  progress  of 
experimental  than  with  astronomical  science. 

Even  when  "  The  Fuel  of  the  Sun"  was  published  I  knew 
nothing  of  the  American  observations  of  the  quadrangular 
figure  of  the  corona,  or  should  certainly  have  then  quoted 
them,  nor  of  the  fact  revealed  by  the  Eclipse  of  December, 
1870,  that,  "  wherever  on  the  solar  disk  a  large  group  of 
prominences  was  seen  on  Mr.  Seabroke's  map,  there  a  corre- 
sponding bulging  out  of  the  corona  was  chronicled  on  Professor 
Watson's  drawing  ;  and  at  the  positions  where  no  prominences 
presented  themselves,  there  the  bright  portions  of  the  corona 
extended  to  the  smallest  distances  from  the  sun's  linib  ;  and 
that  Mr.  Brother's  photographs  all  show  the  corona  extending 
much  farther  toward  the  west  than  toward  the  east,  the  west 
being  "  the  region  richest  in  solar  prominences."  I  am  sorry 


94  SCIENCE   IE"   SHORT   CHAPTERS. 

that  the  limits  of  this  paper  will  not  permit  me  to  enter  more 
fully  into  the  bearings  of  the  recent  studies  of  the  corona  and 
the  prominences  upon  my  explanations  of  solar  phenomena, 
especially  as  the  differences  between  the  inner  and  outer  corona, 
which  still  appear  to  puzzle  astronomers,  are  exactly  what  my 
explanation  demands.  I  must  make  this  the  subject  of  a  sepa- 
'•  rate  paper,  and  proceed  at  once  to  the  next  step  of  the  general 
argument. 

Assuming  that  such  ejections  of  solid  matter  are  poured 
from  the  prominences,  to  what  distances  may  they  travel  ?  In 
attempting  to  answer  this  question,  I  avowedly  ventured  upon 
dangerous  ground,  for  at  the  time  of  writing  I  only  knew  that 
the  force  of  upheaval  of  the  prominences  must  be  enormous, 
probably  sufficient  to  eject  solid  matter  beyond  the  orbit  of  the 
earth,  and  even  beyond  that  of  Mars.  Actual  measurements  of 
the  eruptive  velocity  of  the  solar  prominences  have  since  been 
made,  and  they  are  so  great  as  to  relieve  me  of  my  quantitative 
difficulty,  and  show  that  I  was  quite  justified  in  the  bold  in- 
ference that  these  eruptions  may  account  for  the  zodiacal  light, 
the  zones  of  meteors  into  which  our  earth  is  sometimes  plunged, 
and  even  the  outer  zone  of  larger  bodies,  the  asteroids. 

But  how,  the  reader  will  ask,  can  such  solids,  ejected  from 
the  sun,  acquire  orbital  paths  around  him.  "We  have  been 
taught  that  the  parabola  is  the  necessary  path  of  such  ejec- 
tions." Mr.  Proctor  has  evidently  reasoned  in  this  manner, 
for  in  last  April  number  of  Fraser's  Magazine  he  says  that 
some  of  my  ideas  are  "opposed  to  any  known  laws,  physical  or 
dynamical,"  that  "there  is  nothing  absolutely  .incredible  in 
the  conception  that  masses  of  gaseous,  liquid,  or  solid  matter 
should  be  flung  to  a  height  exceeding  manifold  that  of  the 
loftiest  of  the  colored  prominences  ;  whereas  it  is  not  only 
incredible,  but  impossible,  that  such  matter  should  in  any  case 
come  to  circle  in  a  closed  orbit  round  the  sun." 

More  careful  reading  would  have  shown  Mr.  Proctor  that  I 
have  considered  other  conditions  besides  those  of  the  text- 
books, that  the  case  is  by  no  means  one  of  simple  radial  pro- 
jection from  a  fixed  body  into  free  space  and  undisturbed 
return.  I  distinctly  stated  that  "  the  recent  ejections  may  have 
any  form  of  orbit  within  the  boundaries  of  the  conic  sections," 
from  a  straight  line  returning  upon  itself,  due  to  absolutely 
vertical  projection,  to  a  circular  orbit  produced  by  the 
tangential  projection  of  such  curving  prominences  as  the  ram's 
horn,  etc.  The  outline  of  the  zodiacal  light  would  be  formed 


THE    FUEL   OF  THE   SUN.  9o 

by  the  termination  or  aphelion  portion  of  these  excursions,  or 
of  such  a  number  of  them  as  should  be  sufficient  to  produce  a 
visible  result. 

Again,  speaking  of  the  asteroids,  in  Chapter  14,  I  state  that 
"  I  should  have  expected  a  still  greater  elongation  and  eccentric- 
ity in  some  of  them,  and  such  orbits  may  have  existed  ;  but 
an  asteroid  with  an  orbit  of  cometary  eccentricity  that  would 
in  the  course  of  each  revolution  cross  the  paths  of  Mercury, 
Venus,  the  Earth,  and  Mars,  in  nearly  the  same  plane,  and 
dive  through  the  thickly  scattered  zodiacal  cluster,  both  in 
going  to  the  sun  and  returning  from  it,  would  be  subject  to 
disturbances  which  would  continue  until  one  of  two  things 
occurred.  Its  tangential  force  might  become  so  far  neutralized 
and  its  orbit  so  much  elongated,  that  finally  its  perihelion  dis- 
tance should  not  exceed  the  solar  radius,  when  it  would  finish 
its  course  by  returning  to  the  sun.  On  the  other  hand,  its 
tangential  velocity  might  be  increased  by  heavy  pulls  from 
Jupiter,  when  slowly  turning  its  aphelion  path,  and  be  similarly 
influenced  by  friendly  jerks  in  crossing  the  orbits  of  the 
inferior  planets  ;  and  thus  its  orbit  might  be  widened,  until  it 
ceased  periodically  to  cross  the  path  of  any  of  the  planets  by 
establishing  itself  in  an  orbit  constantly  intermediate  between 
any  two.  Having  once  settled  into  such  a  path,  it  would 
remain  there  with  comparative  stability  and  permanency.  If  I 
am  right  in  this  view  of  the  dynamical  history  of  these  older 
ejections,  all  the  long  elliptical  paths  of  zodiacal  particles, 
meteorites,  or  asteroids,  would  thus  in  the  course  of  ages 
become  eliminated,  and  the  remaining  orbits  would  be  of 
planetary  rather  than  cometary  proportions." 

A  little  reflection  on  the  above-stated  laws  of  dissociation 
will  show  that  the  maximum  violence  of  hydrogen  explosion 
will  not  occur  at  the  birth  of  the  ejections,  but  afterwards, 
when  the  dissociated  gases  have  been  already  hurled  beyond 
the  sphere  of  restraining  vapors.  If  my  explanation  is  correct, 
the  typical  form  of  a  solar  prominence  should  be  that  of  a 
spreading  tree  with  a  tall  stem.  At  first  the  least  resistance  to 
radiation  arid  consequent  explosive  combination  must  be  in  the 
vertical  direction,  as  this  will  afford  the  shortest  line  that  can 
be  drawn  through  the  thickness  of  the  surrounding  jacket  of 
resisting  vapor  ;  but  when  raised  above  this  envelope,  the  dis- 
sociated gases,  cooled  by  their  own  expansion  and  compara- 
tively free  to  radiate  in  all  directions  except  downward,  will 
explode  laterally  as  well  as  vertically,  and  thus  spread  out  into 


96  SCIENCE   IN    SHORT   CHAPTERS. 

a  head.  My  theoretical  prominence  will  be,  in  short,  a  monster 
rocket  proceeding  steadily  upward  to  a  certain  extent,  and 
then  gradually  bursting  and  projecting  its  missiles  in  every 
direction  from  the  vertical  to  the  absolutely  horizontal. 
Should  the  latter  acquire  a  velocity  of  about  300  miles  per 
second,  not  merely  a  closed  but  even  an  absolutely  circular 
orbit  would  be  possible.  These  and  the  multitude  of  weaker 
lateral  ejections,  reaching  the  sun  by  shoit  parabolic  paths, 
explain  the  mystery  of  the  inner  corona. 

I  need  only  refer  Mr.  Proctor  to  his  own  recently  published 
book  on  the  sun,  where  lie  will  find  on  plates  4,  5,  and  6  a 
number  of  drawings  from  Zollner  and  Respighi,  which  so 
thoroughly  confirm  my  necessary  theoretical  deductions  that 
they  might  be  a  series  of  fancy  sketches  of  my  own.  When 
we  consider  that  the  base  of  a  prominence  is  only  visible  when 
it  happens  to  start  exactly  from  the  limb  of  the  sun,  while 
the  vastly  greater  proportion  of  those  which  are  observed,  and 
have  been  drawn,  have  much  of  the  stem  cut  off  from  view  by 
the  solar  rotundity,  the  evidence  afforded  by  such  diawings  in 
support  of  my  theoretical  deduction,  that  the  typical  foim  of 
the  solar  prominences  is  that  of  a  palm-tree  or  bursting  rocket, 
is  greatly  strengthened.* 

In  a  paper  by  P.  Sccclii,  dated  Rome,  March  20th,  3871, 
and  published  in  the  Comptes  Rendus,  March  27th,  this  veteran 
solar  observer  speaks  cf  the  pi  eminences  as  composed  of  jets, 
which,  "  upon  reaching  a  certain  elevation,  stop  and  whirl  upon 
themselves,  giving  birth  to  a  brilliant  cloud."  This  cloud  is 
represented  as  spreading  out  on  all  sides  from  the  summit  of  the 
combined  jets.  Again  he  says,  "It  is  very  common  to  see  a 
little  jet  stop  at  a  certain  elevation  above  the  chromosphere, 
and  there  spread  itself  out  into  a  wide  hat  ("  un  large 
chapeau")  of  an  absolutely  nebulous  constitution."  This  out- 
spreading nebulosity  is  the  flash  of  the  incandescent  vapors 
produced  by  the  explosion  which  is  theoretically  demanded  by 
my  explanation  to  occur  exactly  in  the  manner  and  place 
described.  These  expanded  incandescent  gases  will  be  render- 

*  Any  reader  of  Tlie  Fuel  of  the  Sun  will  perceive  that  the  vaporous 
envelope  which  I  have  described  as  "an  effectual  jacket  for  limiting 
the  amount  of  radiation, "  is  a  complete  theoretical  anticipation  and 
explanation  of  the  "solar  crust"  of  Eespighi  and  the  "Trennung- 
schiokt"  of  Zollner.  We  agree  perfectly  in  our  conclusions,  though 
arriving  at  them  by  such  very  different  paths,  and  so  independently 
of  each  other. 


THE   FUEL   OF   THE   SUIT.  97 

ed  visible  by  the  spectroscopic  dilution  of  the  continuous  spec- 
trum of  the  denser  photosphere,  while  the  solid  projectiles  that 
must  proceed  from  them  in  every  direction  can  only  be  seen 
during  a  solar  eclipse. 

The  observations  and  drawings  of  Zollner  and  Respighi 
were,  for  the  most  part,  made  while  my  book  was  in  the 
press,  and,  like  those  of  Secchi  above  quoted,  were  unknown 
to  me  when  I  wrote  ;  I  was  then  only  able  to  quote,  in  support 
of  my  theoretical  requirements,  the  evidences  of  actually 
observed  tangential  ejection  afforded  by  Sir  John  HerschePs 
account  of  the  great  solar  storm  of  September  1st,  1859. 

Besides  this  direct  tangential  projection  there  are  other  ele- 
ments of  motion  contributing  to  the  same  result,  such  as  the 
whirling  of  the  prominences  on  themselves,  their  motion  of 
translation  on  the  sun's  disk,  and  the  rotation  of  the  sun  itself. 

I  must  now  bring  his  sketch  to  a  close  by  stating  that,  in 
order  to  submit  the  fundamental  question  of  a  universal 
atmosphere  to  an  experimentum  crucis  analogous  to  that  by 
which  Pascal  tested  the  atmospheric  theory  of  Torricelli,  I  have 
calculated  the  theoretical  density  of  the  atmosphere  of  the 
moon  and  of  each  of  the  planets,  and  compared  the  results  as 
severely  as  I  could  with  the  observed  facts.  As  Jupiter  is 
27,100  times  heavier  than  the  moon,  and  between  these  wide 
extremes  there  are  six  planets  presenting  great  variations  of 
mass,  the  probabilities  of  accidental  coincidence  are  over- 
whelmingly against  me,  and  a  close  concurrence  of  observed 
telescopic  refraction  and  other  phenomena  with  the  theoretical 
atmospheric  density  must  afford  the  strongest  possible  con- 
firmation of  the  soundness  of  the  basis  of  my  whole  argument. 
Such  a  concurrence  exists,  and  some  new  and  very  curious 
light  is  unexpectedly  thrown  upon  the  meteorology  of  Mars 
and  the  constitution  of  the  larger  planets.  The  latter,  if  I  am 
right,  must  be  miniature  suns,  permanently  red-  or  white-hot, 
must  have  something  like  a  photosphere,*  surrounded  by  a 
sphere  of  vapor  (the  outside  of  which  we  see),  must  have 
mimic  spot  vortices  and  prominences,  and  in  the  case  of 
Saturn  must  eject  volleys  of  meteoric  matter,  some  of  which 
should  finally  settle  down  into  orbital  paths,  and  thus  produce 
the  rings. 

These  are  startling  conclusions,  and  when  I  reached  them 
they  were  utterly  at  variance  with  general  astronomical  opin- 
ion, but  I  find  since  their  publication  that  some  astronomers 
have  already  shown  considerable  readiness  to  adopt  them.  In 


98  SCIENCE   IN    SHORT    CHAPTERS. 

my  case  this  view  of  the  solar  constitution  of  tie  larger 
planets  is  not  a  matter  of  mere  opinion,  or  guessing,  or  piob- 
ability,  but  it  follows  of  necessity,  and  as  stated  on  page  200, 
"  the  great  mystery  of  Saturn's  rings  is  resolved  into  a  simple 
consequence,  a  demonstrable  and  necessary  result  of  the  opera- 
tion of  the  familiar  forces,  whose  laws  of  action  have  been 
demonstrated  here  upon  the  earth  by  experimental  investiga- 
tion in  our  laboratories.  No  strained  hypotheses  of  imaginary 
forces  are  required,  no  ethers  or  other  materials  are  demand- 
ed, beyond  those  which  are  beneath  our  feet  and  around  our 
heads  here  upon  our  own  planet  ;  all  that  is  necessary  is  to 
grant  that  the  well-known  elements  and  compounds  of  the 
chemist,  and  the  demonstrated  forces  of  the  experimental 
physicist,  exist  and  operate  in  the  places,  and  have  the  quanti- 
ties and  modes  of  distribution  described  by  the  astronomer  ; 
this  simple  postulate  admitted,  these  wondrous  appendages 
spring  into  rational  existence,  and  like  the  eternal  fires  of  the 
sun,  the  barren  surface  of  the  moon,  the  dry  valleys  of  Mer- 
cury, the  hazy  equivocations  of  Venus,  the  seas  and  continents 
and  polar  glaciers  of  Mars,  and  the  cloud- covered  face  of 
Jupiter,  follow  as  necessary  consequences  of  a  universal  atmos- 
phere." 

If  I  am  right  in  ascribing  a  gaseous  condition  to  the  sun  and 
the  larger  planets,  and  tracing  the  maintenance  of  this  condition 
to  the  disturbing  gravitation  of  the  attendant  planets  or  satellites, 
a  solution  of  the  riddle  of  the  nebula;  at  once  presents  itself. 
We  have  only  to  suppose  a  star-cluster  or  group  composed  of 
orbs  of  solar  or  great  planetary  dimensions,  and  that  these  act 
mutually  upon  each  other  as  the  planets  on  our  sun,  or  the  satel- 
lites upon  Saturn,  but  in  a  far  more  violent  degree  owing  to 
the  far  greater  relative  masses  of  the  reacting  elements,  and  we 
obtain  the  conditions  under  which  great  gaseous  orbs  would 
be  not  merely  pitted  on  their  surface,  but  riven  to  their  very 
centres,  moulded  and  shaped  throughout  by  the  whirling  hurri- 
cane of  their  whole  substance.  When  thus  in  the  centre  of  a 
tornado  of  opposing  gravitations  the  tortured  orb  would  be 
twisted  bodily  into  a  huge  vorticose  crater,  into  the  bowels  of 
which  the  aqueous  vapor  would  be  dragged  and  dissociated, 
and  then,  entangled  with  the  inner  matter  of  the  riven  sphere, 
would  be  hurled  upward,  again  to  burst  forth  in  an  explosion 
of  such  magnitude  that  the  original  body  would  be  measurably 
presented  as  a  mere  appendage,  the  rocket  case  of  the  flood  of 
lire  it  had  vomited  forth. 


DR.    SIEMENS'S  THEOBY    OF   THE   SUN.  09 

The  reader  must  complete  the  picture.  If  he  will  take  a 
little  trouble  in  doing  so  he  will  find  that  it  becomes  a  portrait 
of  one  or  the  other  of  the  nebula,  according  to  the  kind  of 
intergravitating  star-cluster  from  which  he  starts.  I  have 
endeavored  to  work  out  some  of  the  details  of  the  nebular  con- 
ditions in  Chapter  20.  In  Chapter  211  have  concluded  by 
showing  the  analogy  between  a  sun  and  the  hydro-electric 
machine,  the  sun  being  the  cylinder  and  the  prominences  the 
steam  jets.  If  issuing  jets  of  high  pressure  steam  have  Ike 
same  properties  at  a  distance  of  93  millions  of  miles  from  the 
earth  as  upon  its  surface,  the  body  of  the  sun  and  the  issuing 
steam  must  be  in  opposite  electrical  conditions,  and  furious 
electrical  excitation  must  result ;  and  if  the  laws  of  electrical 
induction  are  constant  throughout  the  universe,  the  earth  must 
be  as  necessarily  subject  to  solar  electrical  influence  as  to  his 
thermal  radiations.  Thus  the  same  reasoning  which  explains 
the  origin  and  maintenance  of  the  solar  heat  and  light,  the  sun- 
spots,  the  photosphere,  the  chromosphere,  the  sierra,  the  prom- 
inences, the  zodiacal  light,  the  aeorlites  and  asteroids  ;  the 
meteorology  of  the  planets  and  the  rings  of  Saturn,  also  shows 
how  the  electrical  disturbances  which  produce  the  aurora 
borealis  and  direct  the  needle  may  originate. 

Electrical  theories  of  the  corona  and  zodiacal  light,  and 
their  connection  of  some  kind  with  the  aurora  borealis,  have 
been  put  forth  in  many  shapes,  but  so  far  as  I  have  learned 
none  afford  any  explanation  of  the  origin  of  the  electrical  dis- 
turbance. Without  this  they  are  like  the  vortices  of  Descartes, 
which  explained  the  movements  of  the  planets  by  supposing 
another  kind  of  motion  still  more  incomprehensible. 

Explanations  which  are  more  difficult  to  explain  than  the 
phenomena  they  propose  to  elucidate  only  obscure  the  light  of 
true  science,  and  stand  as  impediments  to  the  progress  of 
sound  philosophy. 


CHAPTER  XIII. 

DR.    SIEMENS'S    THEORY  OF    THE    SUN. 

A  PAPER  was  read  on  March  2d,  1882,  by  Dr.  C.  "W. 
Siemens  at  the  Royal  Society,  and  he  published -an  article  on 
"  A  New  Theory  of  the  Sun"  in  the  April  number  of  th<? 


100  SCIENCE   12sr   SHOUT   CHAPTERS. 

Nineteenth  Century.  All  wlio  have  read  my  essay  on  "  The 
Fuel  of  the  Sun"  are  surprised  at  the  statement  with  which 
the  magazine  article  opens — viz.  that  this  "  may  be  termed  a 
first  attempt  to  open  for  the  sun  a  debtor  and  creditor  account, 
inasmuch  as  he  has  hitherto  been  regarded  only  as  a  great 
almoner  pouring  forth  incessantly  his  boundless  wealth  of  heat, 
without  receiving  any  of  it  back." 

Some  of  my  friends  suppose  that  Dr.  Siemens  has  willfuly 
ignored  the  most  important  element  of  my  theory,  and  have 
suggested  indignation  and  protest  on  my  part.  I  am  quite 
satisfied,  however,  that  they  are  mistaken.  I  see  plainly 
enough  that  although  Dr.  Siemens  quotes  my  book,  he  had  not 
read  it  when  he  did  so  ;  that  in  stating  that  "  Grove,  Hum* 
boldt.  Zollner,  and  Mattieu  Williams  have  boldly  asserted 
the  existence  of  a  space  filled  with  matter,"  he  derived  this 
information  from  the  paper  of  Dr.  Sterry  Hunt  which  he  after- 
ward quotes.  This  inference  has  been  continued  by  subse- 
quent correspondence  with  Dr.  Siemens,  who  tells  me  that  he 
saw  the  book  some  years  since,  but  had  not  read  it.  My  con- 
tributions to  the  philosophy  of  solar  physics  would  have  been 
far  more  widely  known  and  better  appreciated  had  I  followed 
the  usual  course  of  announcing  firstly  "  a  working  hypothesis," 
to  warn  others  off  the  ground,  then  reading  a  preliminary 
paper,  then  another  and  another,  arid  so  on  during  ten  or  a 
.dozen  years,  instead  of  publishing  all  at  once  an  octavo  volume 
of  240  pages,  which,  has  proved  too  formidable  even  to  many  of 
those  who  are  specially  interested  in  the  subject. 

I  am  compelled  to  infer  that  this  is  the  reason  why  so  many 
of  the  speculations,  which  were  physical  heresies  when 
expounded  therein,  have  since  become  so  generally  adopted, 
without  corresponding  acknowledgment.  This  is  not  the  place 
for  specifying  the  particulars  of  such  adoptions,  but  I  may 
mention  that  in  due  time  "  An  Appendix  to  the  Fuel  of  the 
Sun,"  including  the  whole  history  of  the  subject,  will  be  pub- 
lished. The  materials  are  all  in  hand,  and  only  await  arrange- 
ment. In  the  mean  time  I  will  briefly  state  some  of  the 
points  of  agreement  and  difference  between  Dr.  Siemens  and 
myself. 

In  the  first  place,  we  both  take  as  our  fundamental  basis  of 
speculation  the  idea  of  a  universal  extension  of  atmospheric 
matter,  and  we  botk  regard  this  as  the  recipient  of  the  diffused 
solar  radiations,  which  are  afterward  recovered  and  recon- 
densed,  or  concentrated.  Thus  our  "  fuel  of  the  sun"  is 


DR.    SIEMENS'S   THEORY,  3.F 

primarily  the  same,  but,  as  will  presently  be  seen,  our  machin- 
ery for  feeding  the  solar  furnace  is  essentially  different. 

Certain  desiccated  pedants  have  sneered  at  my  title,  "  The 
Fuel  of  the  Sun,"  as  "  sensational,"  and  have  refused  to  read 
the  book  on  this  account  ;  but  Dr.  Sterry  Hunt  has  provided 
me  with  ample  revenge.  lie  has  disentombed  an  interesting 
paper  by  Sir  Isaac  Newton,  dated  1675,  in  which  the  same 
sensationalism  is  perpetrated  with  very  small  modification,  Sip 
Isaac  Newton's  title  being  "  Solary  Fuel."  Besides  this,  his 
speculations  are  curiously  similar  to  my  own,  his  fundamental 
idea  being  evidently  the  same,  but  the  chemistry  of  his  time 
was  too  vague  and  obscure  to  render  its  development  possible. 
This  paper  was  neglected  and  set  aside,  was  not  printed  in 
the  Transactions  of  the  Royal  Society,  and  remained  generally 
unknown  till  a  few  months  ago,  when  the  energetic  American 
philosopher  brought  it  forth,  and  discussed  its  remarkable 
anticipations. 

Dr.  Siemens  supposes  that  the  rotation  of  the  sun  effects  a 
sort  of  "fan  action,"  by  throwing  off  heated  atmospheric 
matter  from  his  equatorial  regions,  which  atmospheric  matter 
is  afterward  reclaimed  and  passed  over  to  the  polar  regions  of 
the  sun.  This  interchange  he  describes  as  effected  by  the 
differences  of  pressure  on  the  fluid  envelope  of  the  sun  ;  the 
portion  over  the  polar  regions  being  held  down  by  the  whole 
force  of  solar  gravitation,  while  the  equatorial  atmosphere  is 
subject  to  this  pressure,  or  attraction,  minus  the  centrifugal 
impulse  due  to  solar  rotation.  He  maintains  that  this  "centrif- 
ugal action,  howevqr  small  in  amount  as  compared  with  the 
enormous  attraction  of  the  sun,  would  destroy  the  balance,  and 
determine  a  motion  toward  the  sun  as  regards  the  mass  oppo- 
site the  polar  surface,  and  into  space  as  regards  the  equatorial 
mass."  He  adds  that  "  the  equatorial  current  so  produced, 
owing  to  its  mighty  proportions,  would  flow  outward  into  space, 
to  a  practically  unlimited  distance." 

I  will  not  here  discuss  the  dynamics  of  this  hypothesis  ; 
whether  the  reclaiming  action  of  the  superior  polar  attraction 
would  occur  at  the  vast  distances  from  the  sun  supposed  by 
Dr.  Siemens,  or  much  nearer  home,  and  produce  an  effect  like 
the  recurving  of  the  flame  of  his  own  regenerative  gas-burner  ; 
or,  whether  he  is  right  in  comparing  the  centrifugal  force  at 
the  solar  equator  with  that  of  the  earth,  by  simply  measuring 
the  relative  velocity  of  translation  irrespective  of  angular  ve- 
locity. I  will  merely  suggest  that  in  discussing  these,  it  is 


102  SCIEN.OB   IN   SHORT   CHAPTERS. 

necessary,  in  order  to  do  justice  to  Dr.  Siemens,  to  always  keep 
in  mind  the  assumed  condition  of  a  universal  and  continuous 
atmospheric  medium,  and  not  to  reason,  as  some  have  done 
already,  upon  the  basis  of  a  limited  solar  atmosphere  with  a 
definite  boundary,  from  beyond  which  particles  of  atmospheric 
matter  are  to  be  flung  away  into  vacuous  space,  without  the 
intervention  of  all-pervading  fluid  pressure. 

It  is  evident  that  if  such  fan  action  can  bring  back  all  the 
material  that  has  received  the  solar  radiations,  and  which 
holds  them  either  as  temperature  or  otherwise,  the  restoration 
and  perpetuation  of  solar  energy  will  be  complete,  for  even  the 
heat  received  by  our  earth  and  its  brother  and  sister  planets 
would  still  remain  in  the  family,  as  they  would  radiate  it  into 
the  interplanetary  atmospheric  matter  supposed  to  be  reclaimed 
by  the  sun. 

But,  as  Mr.  Proctor  has  clearly  shown,  the  rays  of  the  sun 
cannot  do  all  the  work  thus  required  for  his  own  restoration 
without  becoming  extinguished  as  regards  the  outside  universe  ; 
and  if  the  other  suns — i.e.  the  stars — do  the  same  they  could 
not  be  visible  to  us. 

Thus  Dr.  Siemens's  theory  removes  our  sun  from  his  place 
among  the  stars,  and  renders  the  great  problem  of  stellar  radia- 
tion more  inscrutable  than  ever  by  thus  putting  the  evidence  of 
our  great  luminary  altogether  out  of  court. 

My  theory,  on  the  contrary,  demands  only  a  gradual  absorp- 
tion of  solar  and  stellar  rays,  such  as  actual  observation  of  their 
varying  splendor  indicates. 

If  space  were  absolutely  transparent,  and  its  infinite  depths 
peopled  throughout,  the  firmament  would  present  to  our  view 
one  continuous  blazing  dome,  as  all  the  spaces  between  the. 
nearer  stars  would  be  filled  by  the  infinity  of  radiations  from 
the  more  distant. 


CHAPTER  XIV. 

THE    ORIGIN    OF    LUNAR    VOLCANOES. 

MANY  theoretical  efforts,  some  of  considerable  violence,  have 
been  made  to  reconcile  the  supposed  physical  contradiction  pre- 
sented by  the  great  magnitude  and  area  of  former  volcanic 
activity  of  the  Moon,  and  the  present  absence  of  water  on  its 


THE   OKIGIN   OF   LU^AR  VOLCANOES.  103 

surface.  So  long  as  we  accept  the  generally  received  belief 
that  water  is  a  necessary  agent  in  the  evolution  of  volcanic 
forces,  the  difficulties  presented  by  the  lunar  surface  are  rather 
increased  than  diminished  by  further  examination  and  specu- 
lation. 

We  know  that  the  lava,  scoriae,  dust,  and  other  products  of 
volcanic  action  on  this  earth  are  mainly  composed  of  mixed 
silicates — those  of  alumina  and  lime  preponderating.  When 
we  consider  that  the  solid  crust  of  the  Earth  is  chiefly  coin- 
posed  of  silicic  acid,  and  of  basic  oxides  and  carbonates  which 
combine  with  silicic  acid  when  heated,  a  natural  necessity  for 
such  a  composition  of  volcanic  products  becomes  evident. 

If  the  Moon  is  composed  of  similar  materials  to  those  of 
the  Earth,  the  fusion  of  its  crust  must  produce  similar  com- 
pounds, as  they  are  formed  independently  of  any  atmospheric 
or  aqueous  agency. 

This  being  the  case,  the  phenomena  presented  by  the  cooling 
of  fused  masses  of  mixed  silicates  in  the  absence  of  water 
become  very  interesting.  Opportunities  of  studying  such  phe- 
nomena are  offered  at  our  great  iron-works,  where  fused  masses 
of  iron  cinder,  composed  mainly  of  mixed  silicates,  are  contin- 
ually to  be  seen  in  the  process  of  cooling  under  a  variety  of 
circumstances. 

I  have  watched  the  cooling  of  such  masses  very  frequently, 
and  have  seen  abundant  displays  of  miniature  volcanic  phenom- 
ena, especially  marked  where  the  cooling  has  occurred  under 
conditions  most  nearly  resembling  those  of  a  gradually  cooling 
planet  or  satellite  ;  that  is,  when  the  fused  cinder  has  been 
inclosed  by  a  solid  resisting  and  contracting  crust. 

The  most  remarkable  that  I  have  seen  are  those  presented  by 
the  cooling  of  the  "  tap  cinder"  from  puddling  furnaces. 
This,  as  it  flows  from  the  furnace,  is  received  in  stout  iron 
boxes  ("cinder-bogies")  of  circular  or  rectangular  horizontal 
section.  The  following  phenomena  are  usually  observable  on 
the  cooling  of  the  fused  cinder  in  a  circular  bogie. 

First  a  thin  solid  crust  forms  on  the  red-hot  surface.  This 
speedily  cools  sufficiently  to  blacken.  If  pierced  by  a  slight 
thrust  from  an  iron  rod,  the  red-hot  matter  within  is  seen  to 
be  in  a  state  of  seething  activity,  and  a  considerable  quantity 
exudes  from  the  opening.  If  a  bogie  filled  with  fused  cinder 
is  left  undisturbed,  a  veritable  spontaneous  volcanic  eruption 
takes  place  through  some  portion,  generally  near  the  centre,  of 
the  solid  crust.  In  some  cases  this  eruption  is  sufficiently 


104  SCIENCE   IN   SHORT   CHAPTERS. 


violent  to  eject  small  spurts  of  molten  cinder  to  a  height  equal 
to  four. or  live  diameters  of  the  whole  mass. 

The  crust  once  broken,  a  regular  crater  is  rapidly  formed, 
and  miniature  streams  of  lava  continue  to  pour  from  it  ;  some- 
times slowJy  and  regularly,  occasionally  with  jerks  and  spurts 
due  to  the  bursting  of  bubbles  of  gas.  The  accumulation  of 
these  lava-streams  forms  a  regular  cone,  the  height  of  which 
goes  on  increasing.  I  have  seen  a  bogie  about  10  or  12  inches 
in  diameter,  and  9  or  10  inches  deep,  thus  surmounted  by  a 
cone  above  5  inches  high,  with  a  base  equal  to  the  whole  diam- 
eter of  the  bogie.  These  cones  and  craters  could  be  but  little 
improved  by  a  modeller  desiring  to  represent  a  typical  volcano 
in  miniature. 

Similar  craters  and  cones  are  formed  on  the  surface  of  cinder 
which  is  not  confined  by  the  sides  of  the  bogie.  I  have  seen 
them  well  displayed  on  the  "  running-out  beds"  of  refinery 
furnaces.  These,  when  filled,  form  a  small  lake  of  molten  iron 
covered  with  a  layer  of  cinder.  This  cinder  first  skins  over,  as  in 
the  bogies,  then  small  crevasses  form  in  this  crust,  and  through 
these  the  fused  cinder  oozes  from  below.  The  outflow7  from 
this  chasm  soon  becomes  localized,  so  as  to  form  a  single  crater, 
or  a  small  chain  of  craters  ;  these  gradually  develop  into  cones 
by  the  accumulation  of  outflowing  lava,  so  that  when  the  whole 
mass  has  solidified,  it  is  covered  more  or  less  thickly  with  a 
number  of  such  hillocks.  These,  however,  are  much  smaller 
than  in  the  former  case,  reaching  to  only  one  or  two  inches  in 
height,  with  a  proportionate  base.  It  is  evident  that  the 
dimensions  of  these  miniature  volcanoes  are  determined  mainly 
by  the  depth  of  the  molten  matter  from  which  they  are  foimed. 
In  the  case  of  the  bogies,  they  are  exaggerated  by  the  over- 
powering resistance  of  the  solid  iron  bottom  and  sides,  which 
force  all  the  exudation  in  the  one  direction  of  least  resistance 
— viz.  toward  the  centre  of  the  thin  upper  crust,  and  thus  a 
single  crater  and  a  single  cone  of  the  large  relative  dimensions 
above  described  are  commonly  formed. 

The  magnitude  and  perfection  of  these  miniature  volcanoes 
.vary  considerably  with  the  quality  of  the  pig-iron  and  the  treat- 
ment it  has  received,  and  the  difference  appears  to  depend 
upon  the  evolution  of  gases,  such  as  carbonic  oxide,  volatile 
chlorides,  fluorides,  etc.  I  mention  the  fluorides  particularly, 
having  been  recently  engaged  in  making  some  experiments  on 
Mr.  Henderson's  process  for  refining  pig-iron,  by  exposing  it 
when  fused  to  the  action  of  a  mixture  of  fluoride  of  calcium 


THE   ORIGIK    OF   LUKAR    VOLCANOES.  105 

and  oxides  of  iron,  alumina,  manganese,  etc.  The  cinder 
separated  from  this  iron  displayed  the  phenomena  above 
described  very  remarkably,  and  jets  of  yellowish  flame  were 
thrown  up  from  the  craters  while  the  lava  was  flowing.  The 
flame  was  succeeded  by  dense  white  vapors  as  the  temperature 
of  the  cindor  lowered,  and  a  deposit  of  snow-like,  flocculent 
crystals  was  left  upon  and  around  the  mouth  or  crater  of  each 
cone.  The  miniature  representation  of  cosmical  eruptions  was 
thus  rendered  still  more  striking,  even  to  the  white  deposit  of 
the  haloid  salts  which  Palmier!  has  described  as  remaining 
after  the  recent  eruption  of  Vesuvius. 

The  gases  thus  evolved  have  not  yet  been  analytically 
examined,  and  the  details  of  the  powerful  reactions  displayed 
in  this  process  still  demand  further  study  ;  but  there  can  be 
no  doubt  that  the  combination  of  silicic  acid  with  the  base  of 
the  fluorspar  is  the  fundamental  reaction  to  which  the  evolu- 
tion of  the  volatile  fluorides,  etc.,  is  mainly  due. 

A  corresponding  evolution  of  gases  takes  place  in  cosmical 
volcanic  action,  whenever  silicic  acid  is  fused  in  contact  with 
limestone  or  other  carbonate,  and  a  still  closer  analogy  is  pre- 
sented by  the  fusion  of  silicates  in  contact  with  chlorides  and 
oxides,  in  the  absence  of  water.  If  the  composition  of  the 
Moon  is  similar  to  that  of  the  Earth,  chlorides  of  sodium,  etc. 
must  form  an  important  part  of  its  solid  crust  ;  they  should 
correspond  in  quantity  to  the  great  deposit  of  such  salts  that 
would  be  left  behind  if  the  ocean  of  the  Earth  were  evaporat- 
ed to  dryness.  The  only  assumptions  demanded  in  applying 
these  facts  to  the  explanation  of  the  surface  configuration  of 
the  Moon  are,  1st,  that  our  satellite  resembles  its  primary  in 
chemical  composition  ;  2d,  that  it  has  cooled  down  from  a 
state  of  fusion  ;  and  3d,  that  the  magnitude  of  the  eruptions, 
due  to  such  fusion  and  cooling,  must  bear  some  relation  to  the 
quantity  of  matter  in  action. 

The  first  and  second  are  so  commonly  made  arid  understood, 
that  I  need  not  here  repeat  the  well-known  arguments  upon 
which  they  are  supported,  but  may  remark  that  the  facts  above 
described  afford  new  and  weighty  evidence  in  their  favor. 

If  the  correspondence  between  the  form  of  a  freely  sus- 
pended and  rotating  drop  of  liquid  and  that  of  a  planet  or 
satellite  is  accepted  as  evidence  of  the  exertion  of  the  same 
forces  of  cohesion,  etc.  on  both,  the  correspondence  between 
the  configuration  of  the  lunar  surface,  and  that  of  small  quan- 
tities of  fused  and  freely  cooled  earth-crust  matter,  should  at 


106  SCIENCE   IX   SHORT   CHAPTERS. 

least  afford  material  support  to  the  otherwise-indicated  infer- 
ence, that  the  materials  of  the  Moon's  crust  are  similar  to 
those  of  the  Earth's,  and  that  they  have  been  cooled  from  a 
state  of  fusion. 

I  think  I  jnay  safely  generalize  to  the  extent  of  saying,  that 
no  considerable  mass  of  fused  earthy  silicates  can  cool  down 
under  circumstances  of  free  radiation  without  first  forming  a 
heated  solid  crust,  which,  by  further  radiation,  cooling,  and 
contraction,  will  assume  a  surface  configuration  resembling 
more  or  less  closely  that  of  the  Moon.  Evidence  of  this  is 
afforded  by  a  survey  of  the  spoil -banks  of  blast  furnaces, 
where  thousands  of  blocks  of  cinder  are  heaped  together,  all 
of  which  will  be  found  to  have  their  upper  surfaces  (that  were 
freely  exposed  when  cooling)  corrugated  with  radiating  mini- 
ature lava  streams,  that  have  flowed  from  one  or  more  craters 
or  openings  that  have  been  formed  in  the  manner  above  de- 
scribed. The  third  assumption  will,  I  think,  be  at  once  ad- 
mitted, inasmuch  as  it  is  but  the  expression  of  a  physical 
necessity. 

According  to  this,  the  Earth,  if  it  has  cooled  as  the  Moon  is 
supposed  to  have  done,  should  have  displayed  corresponding 
irregularities,  and  generally,  the  magnitude  of  mountains  of 
solidified  planets  and  satellites  should  be  on  a  scale  proportion- 
ate to  their  whole  mass.  In  comparing  the  mountains  of  the 
Moon  and  Mercury  with  those  of  the  Earth,  a  large  error  is 
commonly  made  by  taking  the  customary  measurements  of 
terrestrial  mountain-heights  from  the  sea-level.  As  those  por- 
tions of  the  Earth  which  rise  above  the  waters  are  but  its 
upper  mountain  slopes,  and  the  ocean  bottom  forms  its  lower 
plains  and  valleys,  we  must  add  the  greatest  ocean  depths  to 
our  customary  measurements,  in  order  to  state  the  full  height 
of  what  remains  of  the  original  mountains  of  the  Earth.  As 
all  the  stratified  rocks  have  been  formed  by  the  wearing  down 
of  the  original  upper  slopes  and  summits,  we  cannot  expect  to 
be  able  to  recognize  the  original  skeleton  form  of  our  water- 
washed  globe. 

If  my  calculation  of  the  atmosphere  of  Mercury  is  correct — 
viz.  that  its  pressure  is  equal  to  about  one  seventh  of  the 
Earth's,  or  4J-  inches  of  mercury,  there  can  be  no  liquid  water 
on  that  planet,  excepting  perhaps  over  a  small  amount  of  cir- 
cunipolar  area,  and  during  the  extremes  of  its  aphelion  winter. 
Thus  the  irregularities  of  the  terminator,  indicating  mountain 
elevations  calculated  to  reach  to  --  of  the  diameter  of  the 


THE   ORIGIN   OF   LUNAR  VOLCANOES.  107 

planet,  are  quite  in  accordance  with  the  above-stated  theoreti- 
cal considerations. 

There  is  one  peculiar  feature  presented  by  the  cones  of  the 
cooling  cinder  which  is  especially  interesting.  The  flow  of 
fused  cinder  from  the  little  crater  is  at  first  copious  and  con- 
tinuous ;  then  it  diminishes  and  becomes  alternating,  by  a  ris- 
ing and  falling  of  the  fused  mass  within  the  cone.  Ultimately 
the  flow  ceases,  and  then  the  inner  liquid  sinks,  more  or  less, 
below  the  level  of  the  orifice.  In  some  cases,  where  much  gas 
is  evolved,  this  sinking  is  so  considerable  as  to  leave  the  cone 
as  a  mere  hollow  shell  ;  the  inner  liquid  having  settled  down 
and  solidified  with  a  flat  or  slightly  rounded  surface,  at  about 
the  level  of  the  base  of  the  cone,  or  even  lower.  These  hollow 
cones  were  remarkably  displayed  in  some  of  the  cinder  of  the 
Henderson  iron,  and  their  formation  was  obviously  promoted 
by  the  abundant  evolution  of  gas. 

If  such  hollow  cones  were  formed  by  the  cooling  of  a  mass 
like  that  of  the  Moon,  they  would  ultimately  and  gradually 
subside  by  their  own  weight.  But  how  would  they  yield  ? 
Obviously,  by  a  gradual  hinge-like  bending  at  the  base  toward 
the  axis  of  the  cone.  This  would  occur  with  or  without  fract- 
ure, according  to  the  degree  of  viscosity  of  the  crust  and  the 
amount  of  inclination.  But  the  sides  of  the  hollow-cone  shell, 
in  falling  toward  the  axis,  would  be  crushing  into  smaller  cir- 
cumferences. "What  would  result  from  this  ?  I  think  it  must 
be  the  formation  of  fissures,  extending,  for  the  most  part, 
radially  from  the  crater  toward  the  base,  and  a  crumpling  up 
of  the  shell  of  the  cone  by  foldings  in  the  same  direction. 
Am  I  venturing  too  far  in  suggesting  that  in  this  manner  may 
have  been  formed  the  mysterious  rays  and  rills  that  extend  so 
abundantly  from  several  of  the  lunar  craters  ? 

The  upturned  edges  or  walls  of  the  broken  crust,  and  the 
chasms  necessarily  gaping  between  them,  appear  to  satisfy  the 
peculiar  phenomena  of  reflection  which  these  rays  present. 
These  edges  of  the  fractured  crust  would  lean  toward  each 
other,  and  form  angular  chasms  ;  while  the  foldings  of  the 
crust  itself  would  form  long  concave  troughs,  extending  radially 
from  the  crater. 

These,  when  illuminated  by  rays  falling  upon  them  in  the 
direction  of  the  line  of  vision,  must  reflect  more  light  toward 
the  spectator  than  does  the  general  convex  lunar  surface,  and 
thus  they  become  especially  visible  at  the  full  Moon. 

Such  foldings  and  fractures  would  occur  after  the  subsidence 


108  SCIENCE   IN   SHORT   CHAPTERS. 

and  solidification  of  the  lava-forming  liquid — that  is,  when  the 
formation  of  new  craters  had  ceased  in  any  given  region  ; 
hence  they  would  extend  across  the  minor  lateral  craters 
formed  by  outbursts  from  the  sides  of  the  main  cone,  in  the 
manner  actually  observed. 

The  fact  that  the  bottoms  of  the  great  walled  craters  of  the 
Moon  are  generally  lower  than  the  surrounding  plains  must  not 
be  forgotten  in  connection  with  this  explanation. 

I  will  not  venture  further  with  the  speculations  suggested  by 
the  above -described  resemblances,  as  my  knowledge  of  the 
details  of  the  telescopic  appearances  of  the  Moon  is  but 
second-hand.  I  have  little  doubt,  however,  that  observers 
who  have  the  privilege  of  direct  familiarity  with  such  details 
will  find  that  the  phenomena  presented  by  the  cooling  of  iron 
cinder,  or  other  fused  silicates,  are  worthy  of  further  and  more 
careful  study. 


CHAPTER  XV. 

NOTE    ON    THE    DIRECT    EFFECT    OF    SUN-SPOTS    ON    TERRESTRIAL 
CLIMATES. 

PROFESSOR  LANGLEY  determines  quantitatively  the  effects 
respectively  produced  by  the  radiations  from  the  solar  spots, 
penumbra,  and  photosphere  upon  the  face  of  a  thermopile,  and 
infers  that  these  effects  measure  their  relative  influence  on 
terrestrial  climate. 

In  thus  assuming  that  the  heat  communicated  to  the  ther- 
mopile measures  the  solar  contribution  to  terrestrial  climate, 
Professor  Langley  omits  an  important  factor — viz.  the  amount 
of  heat  absorbed  in  traversing  the  earth's  atmosphere  ;  and  in 
measuring  the  relative  efficiency  of  the  spots,  penumbra,  and 
photosphere,  he  has  not  taken  into  account  the  variations  of 
diathermancy  of  the  intervening  atmospheric  matter,  which 
are  due  to  the  variations  in  the  source  of  heat. 

Speaking  generally,  it  may  be  affirmed  that  the  radiations  of 
obscure  heat  are  more  largely  absorbed  by  the  gases  and  vapors 
of  our  atmosphere  than  those  of  luminous  heat,  and  the  great 
differences  in  the  mere  luminosity  of  the  spots,  penumbra,  and 
photosphere  justify  the  assumption  that  the  radiations  of  a 


NOTE   ON   THE    DIRECT   EFFECT   OF   SUK-SPOTS.       109 

sun-spot  will  (to  use  the  expressive  simile  of  Tyndall)  lose  far 
more  by  atmospheric  sifting  than  will  those  from  the  photo- 
sphere. 

But  the  spot  areas  will  be  none  the  less  effective  on  terrestrial 
climate  on  that  account.  A  given  amount  of  heat  arrested  by 
the  earth's  atmosphere  will  have  even  greater  climatic  efficiency 
than  if  received  upon  its  solid  surface,  inasmuch  as  the  gases 
are  worse  radiators  than  the  rocks,  and  will  therefore,  cceteris 
paribus,  retain  a  larger  proportion  of  the  heat  they  receive. 

I  have  long  ago  endeavored  to  show  *  that  the  depth  of  the 
photosphere,  from  the  solar  surface  inward,  is  limited  by  dis- 
sociation ;  that  the  materials  of  the  Sun  within  the  photosphere 
exist  in  a  dissociated,  elementary  condition  ;  that  at  the 
photosphere  they  are,  for  the  most  part,  combined.  This  view 
has  since  been  adopted  by  many  eminent  solar  physicists,  and, 
if  correct,  demands  a  much  higher  temperature  within  the 
depths  revealed  by  that  withdrawal  of  the  photospheric  veil 
which  constitutes  a  sun-spot. 

If  I  am  right  in  this,  and  also  in  supposing  the  spot-radia- 
tions to  be  so  much  more  abundantly  absorbed  than  those  of 
the  photosphere,  and  if  in  spite  of  this  higher  temperature  of 
the  spots,  the  surface  of  the  earth  receives  from  them  the 
lower  degree  of  heat  measured  by  Professor  Langley,  another 
interesting  consequence  must  follow.  The  excess  of  spot- 
heat  directly  absorbed  by  the  atmosphere,  and  mainly  by  the 
water  dissolved  or  suspended  in  its  upper  regions,  must  be 
especially  effective  in  dissipating  clouds  and  checking  or 
modifying  their  formation.  The  meteorological  results  of  this 
may  be  important,  and  are  worthy  of  careful  study. 

In  thus  venturing  to  question  some  of  Professor  Langley's 
inferences  I  am  far  from  underrating  the  interest  and  impor- 
tance of  his  researches.  On  the  contrary,  I  regard  the  quanti- 
tative results  he  has  obtained  as  especially  valuable  and  oppor- 
tune, in  affording  means  of  testing  the  above-named  and  other 
speculations  in  solar  physics.  Similar  observations  repeated 
at  different  elevations  would  decide,  so  far  as  the  lower  regions 
are  concerned,  whether  or  not  there  is  any  difference  in  the 
quantity  of  heat  imparted  by  the  bright  and  obscure  portions 
of  the  Sun  to  our  atmosphere.  If  the  differences  already 
observed  by  Professor  Langley  vary  in  ascending,  a  new 
means  will  be  afforded  of  studying  the  constitution  of  the  in- 

*  "  The  Fuel  of  the  Sun,"  Chapters  iv.  to  x. 


110  SCIENCE   Itf   SHORT   CHAPTERS. 

terior  of  the  Sun  and  its  relations  to  the  photosphere.  Direct 
evidence  of  selective  absorption  by  our  atmosphere  may  thus  be 
obtained,  which  would  go  far  toward  solving  one  of  the  cru- 
cial solar  problems — viz.  whether  the  darker  regions  are  hotter 
or  cooler  than  the  photosphere. 

The  obscure  radiations  from  the  moon  must  be  absorbed  by 
our  atmosphere  like  those  from  the  sun-spot,  and  may  be  suffi- 
ciently effective  to  account  for  the  alleged  dissipation  of  clouds 
by  the  full  moon. 

In  both  cases  the  climatic  influence  is  greatly  heightened  by 
the  fact  that  all  the  heat  thus  absorbed  is  directly  effective  in 
raising  the  temperature  of  the  air.  The  action  of  the 
absorbed  heat  in  reference  to  cloud  -  formation  is  directly 
opposite  to  that  of  the  transmitted  solar  heat,  as  this  reaching 
the  surface  of  the  earth  evaporates  the  superficial  water,  and 
thereby  produces  the  material  of  clouds.  On  the  other  hand, 
the  heat  which  is  absorbed  by  the  air  increases  its  vapor-hold- 
ing capacity,  and  thus  prevents  the  formation  of  clouds,  or 
even  effects  the  dissolution  of  clouds  already  formed. 


CHAPTER   XVI. 

THE    PHILOSOPHY    OF    THE    RADIOMETER    AND    ITS    CO.JMI-2AL 

REVELATIONS. 

So  much  speculation,  and  not  a  little  extravagant  specula- 
tion, has  been  devoted  to  the  dynamics  of  the  radiometer, 
that  I  feel  some  compunction  in  adding  another  stone  to  the 
heap,  my  only  apology  and  justification  for  so  doing  being 
that  I  propose  to  regard  the  subject  from  a  very  unsophisti- 
cated point  of  view,  and  with  somewhat  heretical  directness  o! 
vision — i.e.  quite  irrespective  of  atoms,  molecules,  or  ether,  or 
any  other  specific  preconceptions  concerning  the  essential 
kinetics  of  radiant  forces,  beyond  that  of  regarding  such  ford  s 
as  affections  or  conditions  of  matter  which  arc  transmitted 
radially  in  constant  qu?mtity,  and  therefore  obey  the  necessMi-y 
law  of  radial  diffusion  or  inverse  squares. 

The  primary  difficulty  which  appears  to  have  generally  been 
suggested  by  the  movements  of  the  radiometer,  is  the  case 


THE    PHILOSOPHY    OF   THE    RADIOMETER.  Ill 

which  it  seems  to  present  of  mechanical  action  without  any 
visible  basis  of  corresponding  reaction  :  a  visible  tangible 
object  pushed  forward,  without  any  visible  pushing  agent  or 
resisting  fulcrum  against  which  the  moving  body  reacts. 

This  difficulty  has  been  met  by  the  invocation  of  obedient 
and  vivacious  molecules  of  residual  atmospheric  matter,  which 
have  been  called  upon  to  bound  and  rebound  between  the  vanes 
and  the  inner  surfaces  of  the  glass  envelope  of  the  instrument. 

How  is  it  that  the  advocates  of  these  activities  have  not 
sought  to  verify  their  speculations  by  modifying  the  shape  and 
dimensions  of  the  exhausted  glass  bulb  or  receiver  ?*  If  the 
motion  of  the  radiometer  is  due  to  such  excursions  and  colli- 
sions, the  length  of  excursion  and  the  angles  of  collision  must 
modify  its  motions  ;  and  such  modification  under  given  con- 
ditions would  form  a  fine  subject  for  the  exercise  of  the  inge- 
nuity of  molecular  mathematicians.  If  their  hypothetical  data 
are  sound,  they  should  be  able  to  predict  the  relative  velocities 
or  torsion-force  of  a  series  of  radiometers  of  similar  construc- 
tion in  all  other  respects,  but  with  variable  shapes  and  diam- 
eters of  inclosing  vessels. 

If  we  divest  our  minds  of  all  visions  of  hypothetical  atoms, 
molecules,  ethers,  etc.,  and  simply  look  at  the  facts  of  radia- 
tion with  the  same  humility  of  intellect  as  we  usually  regard 
gravitation,  this  primary  difficulty  of  the  radiometer  at  once 
vanishes.  The  force  of  gravitation  is  a  radiant  force  acting 
somehow  between,  or  upon,  or  by  distant  bodies  ;  and  these 
bodies,  however  far  apart,  act  and  react  upon  each  other  with 
mutual  forces,  precisely  equal  and  exactly  contrary.  We  con- 
ceive the  sun  pulling  the  earth  in  a  certain  direction,  and 
receiving  from  the  earth  an  equal  pull  in  a  precisely  contrary 
direction,  and  we  have  hitherto  demanded  no  ethereal  or 
molecular  link  for  the  transmission  of  these  mutually  attractive 
forces.  Why,  then,  should  we  not  regard  radiant  repulsive 
energy  in  the  same  simple  manner  ? 

If  we  do  this  there  is  no  difficulty  in  finding  the  ultimate 
reaction  fulcrum  of  the  radiometer  vanes.  It  is  simply  the 
radiating  body,  the  match,  the  candle,  the  lamp,  the  sun,  or 
whatever  else  may  be  the  source  of  the  impelling  radiations. 
According  to  this  view,  the  radiant  source  must  be  repelled 
with  precisely  the  same  energy  as  the  arms  or  pendulum  of  the 

*  Since  this  was  written  some  such  modifications  have  been  made 
with  equivocal  results. 


112  SCIEXCE   IX    SHORT   CHAPTERS. 

radiometer  ;  and  it  would  move  backward  or  in  opposite  direc- 
tion if  equally  free  to  move.  If,  by  any  means,  we  cause  the 
glass  envelope  of  the  radiometer  to  become  the  radiant  source, 
it  should  be  repelled,  and  may  even  rotate  in  opposite  direction 
to  the  vanes,  or  vice  versd.  This  has  been  done  with  floating 
radiometers. 

Viewed  thus  as  simple  matter  of  fact,  irrespective  of  any 
preconceived  kinetics  of  intervening  media,  the  net  result  of 
Mr.  Crookes's  researches  become  nothing  less  than  the  dis- 
covery of  a  new  law  of  nature  of  great  magnitude  and  the 
broadest  possible  generality — viz.  that  the  sun  and  all  other 
radiant  bodies — i.e.  all  the  materials  of  the  universe — exert  a 
mechanical  repulsive  force,  in  addition  to  the  calorific,  lumi- 
nous, actinic,  and  electrical  forces  with  which  they  have  hitherto 
been  credited.  He  has  shown  that  this  force  is  refrangible  and 
dispersible,  that  it  is  outspread  with  the  spectrum,  but  is  most 
concentrated,  or  active,  in  the  region  of  the  ultra-red  rays,  and 
progressively  feeblest  in  the  violet  ;  or,  otherwise  stated,  it 
exists  in  closer  companionship  with  heat  than  with  light,  and 
closer  with  light  than  with  actinism. 

According  to  the  doctrine  of  exchanges,  which  has  now 
passed  from  the  domain  of  theory  to  that  of  demonstrated  law, 
all  bodies,  whatever  be  their  temperature,  are  perpetually 
radiating  heat-force,  the  amount  of  which  varies,  cceteris paribux, 
with  their  temperature.  If  we  now  add  to  this  generalization 
that  all  bodies  are  similarly  radiating  mechanical  force  and 
suffering  corresponding  mechanical  reaction,  the  theoretical 
difficulties  of  the  radiometer  vanish.  What  must  follow  in  the 
case  of  a  freely  suspended  body  unequally  heated  on  opposite 
sides  ? 

It  must  be  repelled  in  a  direction  perpendicular  to  the  sur- 
face of  its  hottest  side.  If  two  rockets  were  affixed  to  opposite 
sides  of  a  pendent  body,  and  were  to  exert  unequal  ejective 
forces,  the  reaction  of  the  stronger  rocket  would  repel  the 
body  in  the  opposite  direction  to  its  preponderating  ejection. 
This  represents  the  radiometer  vane  with  one  side  blackened 
and  the  other  side  bright.  When  exposed  to  luminous  rays 
the  black  side  becomes  warmer  than  the  bright  side  by  its 
active  absorption  and  conversion  of  light  into  heat,  and  thus 
the  blackened  face  radiates  in  excess  and  recedes. 

We  may  regard  it  thus  as  reacting  by  its  own  radiations,  or 
otherwise  as  acted  upon  by  the  more  powerful  radiant  whoso 
rays  are  differentially  received  by  the  black  and  bright  sides. 


THE   PHILOSOPHY   OF  THE   RADIOMETER.  113 

These  different  modes  of  regarding  the  action  are  perfectly 
consistent  with  each  other,  and  analogous  to  the  two  different 
modes  of  regarding  gravitation,  when  we  describe  the  sun  as 
attracting  the  earth,  or,  otherwise,  the  earth  as  gravitating  to 
the  sun.  Strictly  speaking,  neither  of  these  descriptions  is 
correct,  as  the  gravitation  is  mutual,  and  the  total  quantity 
exerted  betsveen  the  sun  and  the  earth  is  equal  to  the  sum  of 
their  energies,  but  it  is  sometimes  convenient  to  regard  the 
action  from  a  solar  standpoint,  and  at  others  from  a  terrestrial. 
So  with  the  radiometer  and  the  strictly  mutual  repulsions 
between  it  and  the  predominating  radiant. 

It  appears  to  me  that  this  unsophisticated  conception  of 
radiant  mechanical  repulsive  force,  and  its  necessary  mechanical 
reaction  on  the  radiant  body,  meets  all  the  facts  at  present 
revealed  by  the  experiments  of  Mr.  Crookes  and  others. 

The  attraction  which  occurs  when  the  disk  of  the  radiometer 
is  surrounded  with  a  considerable  quantity  of  atmospheric 
matter  is  probably  due  to  inequality  of  atmospheric  pressure. 
The  absorbing  face  of  the  disk  becomes  heated  above  the 
temperature  of  the  opposite  face,  the  film  of  air  in  contact  with 
the  warmer  face  rises,  leaving  a  relatively  vacuous  space  in 
front.  This  produces  a  rush  of  air  from  back  to  front  which 
carries  the  radiometer  vane  with  it.  When  the  exhaustion  of 
the  radiometer  is  carried  so  far  that  the  residual  air  is  only  just 
sufficiently  dense  to  neutralize  the  direct  repulsion  of  radiation, 
the  neutral  point  is  reached.  When  exhaustion  is  carried 
beyond  this,  repulsion  predominates. 

Taking  Mr.  Crookcs's  estimate  of  the  mechanical  energy  of 
solar  radiation  at  32  grains  per  square  foot,  2  cwts.  per  tcre, 
57  tons  per  square  mile,  etc.,  and  accepting  these  as  they  are 
offered — i.e.  merely  as  provisional  and  approximate  estimates — 
we  are  led  to  a  cosmical  inference  of  the  highest  importance, 
one  that  must  materially  modify  our  interpretations  of  some  of 
the  grandest  phenomena  of  the  universe.  Although  the  esti- 
mated sunlight  pressure  upon  the  earth,  the  three  thousand 
millions  of  tons,  is  too  small  a  fraction  of  the  earth's  total 
weight  to  effect  an  easily  measurable  increase  of  the  length  of 
our  year,  the  case  is  quite  otherwise  with  the  asteroids  and  the 
zones  of  meteoric  matter  revolving  around  the  sun. 

The  mechanical  repulsion  of  radiation  is  a  superficial  action, 
and  must,  therefore,  vary  with  the  amount  of  surface  exposed, 
while  that  of  gravitation  varies  with  the  mass.  Thus  the  ratio 
of  radiant  repulsion  to  the  attraction  of  gravitation  goes  on 


114  SCIENCE   IK    SHORT   CHAPTERS. 

increasing  with  the  subdivision  of  masses,  and  becomes  an 
important  fraction  in  the  case  of  the  smaller  bodies  of  the  solar 
system.  A  zone  of  meteorites  travelling  around  the  sun  would 
be  broken  up,  sifted,  and  sorted  into  different  orbits,  according 
to  their  diameters,  if  this  superficial  repulsion  operated  against 
gravitation  without  any  compensating  agency.  Gravitation 
would  be  opposed  in  various  degrees,  neutralized,  and,  in  the 
case  of  cosmic  dust,  even  reversed.  Comets  presenting  so 
large  a  surface  in  proportion  to  their  mass  would  either  be 
driven  away  altogether  or  forced  to  move  in  orbits  utterly 
disobedient  to  present  calculations.  This  would  occur  if  the 
interplanetary  spaces  were  as  nearly  vacuous  as  the  torsion 
instrument  with  which  Mr.  Crookes  made  his  measurements. 

Regarding  the  properties  of  our  atmosphere  only  in  the  light 
of  experimental  data,  irrespective  of  imaginary  molecules,  and 
their  supposed  gyrations  or  oscillations,  we  see  at  once  that  an 
interplanetary  or  inter-stellar  vacuum  must  act  like  a  Sprengel 
pump  upon  our  atmosphere,  upon  the  atmosphere  of  other 
planets,  and  upon  those  of  the  sun  and  the  stais,  and  would 
continue  such  action  until  an  equilibrium  between  the  repulsive 
energy  of  the  gas  and  the  gravitation  of  the  solid  orbs  had 
been  established.  Atmospheric  matter  would  thus  be  univer- 
sally diffused,  with  special  accumulations  around  solid  orbs, 
varying  in  quantity  with  their  respective  gravitating  energy. 
Such  a  universal  atmosphere  would  accelerate  oibital  motion, 
and  this  acceleration  would  vary  with  the  surface  of  bodies. 
Its  action  being  thus  exactly  opposed  to  that  of  radiant  repul- 
sion, it  must,  at  a  certain  density,  exactly  neutralize  it.  That 
it  d^es  this  is  evident  from  the  obedience  of  all  the  elements 
of  the  solar  system  to  the  calculated  action  of  gravitation  ;  and 
thus  Mr.  Crookes's  researches  not  only  confiim  the  idea  of 
universal  atmospheric  diffusion,  but  they  afford  a  means  by 
which  we  may  ultimately  measure  the  actual  density  of  the 
••  universal  atmosphere.  If,  as  I  have  endeavored  to  show  in  my 
1  essay  on  "  The  Fuel  of  the  Sun,"  the  initial  radiant  energy  of 
every  star  depends  upon  its  mass,  and  its  consequent  condensa- 
tion of  atmospheric  matter,  the  density  of  interplanetary 
atmosphere  sufficient  to  neutralize  the  radiant  mechanical  energy 
of  our  sun  may  be  the  same  as  is  demanded  to  perform  the 
same  function  for  all  the  stars  of  the  universe,  and  all  their 
attendant  worlds,  comets,  and  meteors. 

In  order  to  prevent  misunderstanding  of  the  above,  I  must 
add  that  I  have  therein  studiously  assumed  a  negative  position 


THE   PHILOSOPHY   OF  THE   BADIOMETEK.  115 

in  reference  to  all  hypothetical  conceptions  of  the  nature  of 
heat,  light,  etc.,  and  their  modes  of  transmission,  simply 
because  I  feel  satisfied  that  the  subject  has  hitherto  been 
obscured  and  complicated  by  overstrained  efforts  to  fit  the 
phenomena  to  the  excessively  definite  hypotheses  of  modern 
molecular  mathematicians.  The  atoms  invented  by  Dalton  for 
the  purpose  of  explaining  the  demonstrated  laws  of  chemical 
combination  performed  this  function  admirably,  and  had  great 
educational  value,  so  long  as  their  purely  imaginary  origin  was 
kept  in  view  ;  but  when  such  atoms  are  treated  as  facts,  and 
physical  dogmas  are  based  upon  the  assumption  of  their  actual 
existence,  they  become  dangerous  physical  superstitions. 
Regarding  matter  as  continuous — i.e.  supposing  it  to  be  simply 
is  it  appears  to  be,  and  co-extensive  with  the  universe,  in  ac- 
cordance with  the  experimental  evidences  of  the  unlimited 
expansibility  of  gaseous  matter — we  need  only  assume  that  our 
sensations  of  heat,  light,  etc.  are  produced  by  active  condi- 
tions of  such  matter  analogous  to  those  which  are  proved  to 
produce  our  sensation  of  sound.  On  this  basis  there  is  no 
difficulty  in  conceiving  the  rationale  of  the  reaction  which 
produces  the  repulsion  of  the  radiometer.  I  may  even  go 
further,  and  affirm  that  it  is  impossible  to  rationally  conceive 
radiation  producing  any  mechanical  effects  without  mechanical 
reaction.  If  heat  be  motion,  and  actual  motion  of  actual 
matter,  mechanical  force  must  be  exerted  to  produce  it,  and  a 
body  which  is  warmer  on  one  side  than  the  other — i.e.  which  is 
exerting  more  outward  motion-producing  force  on  one  side 
than  on  the  other — must  be  subject  to  proportionally  unequal 
reaction,  and,  therefore,  if  free  to  move,  must  retreat  in  a  direc- 
tion contrary  to  that  of  its  greater  activity.  Regarded  thus, 
the  residual  air  of  the  radiometer  does  act,  not  by  collisions  of 
particles  between  the  vane  and  inside  of  the  glass  vessel,  but 
by  the  direct  reaction  of  the  radiant  energy  which  would 
operate  irrespective  of  vessels — i.e.  upon  naked  radiometer 
vanes  if  carried  half  way  to  the  moon,  or  otherwise  freed  from 
excess  of  atmospheric  embarrassment. 

The  recent  experiments  of  Mr.  Crookes,  showing  retardation 
of  the  radiometer  with  extreme  exhaustion,  seem  to  indicate 
that  heat-rays,  like  the  electric  discharge,  demand  a  certain 
amount  of  atmospheric  matter  as  their  carrier. 

I  cannot  conclude  these  hasty  and  imperfect  notes,  written 
merely  with  suggestive  intent,  without  quoting  a  passage  from 
thft  preface  to  the  '  Correlation  of  Physical  Forces,'  which, 


116  SCIENCE   Itf   SHORT   CHAPTERS. 

though   written    so  long   ago,   appears  to  ine  worthy  of   the 
profoundest  present  consideration. 

"  It  appears  to  me  that  heat  and  light  may  be  considered  as 
affections  ;  or,  according  to  the  undulatory  theory,  vibrations 
of  matter  itself,  and  not  of  a  distinct  ethereal  fluid  permeating 
it  :  these  vibrations  would  be  propagated  just  as  sound  is 
propagated  by  vibrations  of  wood  or  as  waves  by  water.  To 
my  mind  all  the  consequences  of  the  undulatory  theory  flow  as 
easily  from  this  as  from  the  hypothesis  of  a  specific  ether  ;  to 
suppose  which — namely,  to  suppose  a  fluid  sui  generis  and  of 
extreme  tenuity  penetrating  solid  bodies — we  must  assume,  first, 
the  existence  of  the  fluid  itself  ;  secondly,  that  bodies  are 
without  exception  porous  ;  thirdly,  that  these  pores  communi- 
cate ;  fourthly,  that  matter  is  limited  in  expansibility.  None 
of  these  difficulties  apply  to  the  modification  of  this  theory 
which  I  venture  to  propose  :  and  no  other  difficulty  applies  to 
it  which  does  not  equally  apply  to  the  received  hypothesis.'* 


CHAPTER  XVII. 

ON    THE    SOCIAL    BENEFITS    OF    PARAFFINS. 

To  the  inhabitants  of  Jupiter,  who  have  always  one,  two,  or 
three  of  their  four  moons  in  active  and  efficient  radiation,  or 
of  Saturn  displaying  the  broad  luminous  oceans  of  his  mighty 
rings  in  addition  to  the  minor  lamps  of  his  eight  ever-changeful 
satellites,  the  relative  merits  of  rushlights,  candles,  lamps,  and 
gaslights  may  be  a  question  of  indifference  ;  but  to  us,  the 
residents  of  a  planet  which  has  but  one  small  moon  that  only 
displays  her  nearly  full  face  during  a  few  nights  of  each  month, 
the  subject  of  artificial  light  is  only  second  in  importance  to 
those  of  food  and  artificial  heat,  and  every  step  that  is  made 
in  the  improvement  of  our  supplies  of  this  primary  necessary 
must  have  a  momentous  influence  on  the  physical  comfort,  and 
also  upon  the  intellectual  and  moral  progress,  of  this  world's 
human  inhabitants. 

If  a  cockney  Rip  Van  Winkle  were  to  revisit  his  old  haunts, 
the  changes  produced  by  the  introduction  of  gas  would  probably 
surprise  him  the  most  of  all  he  would  see.  He  would  be 


Oitf   THE   SOCIAL   BENEFITS   OF   PARAFFIXE.  117 

astonished  to  find  respectable  people,  and  even  unprotected 
females,  going  alone,  unarmed  and  without  fear,  at  night,  up 
the  by-streets  which  in  his  days  were  deemed  so  dangerous, 
and  he  would  soon  perceive  that  the  bright  gaslights  had  done 
more  than  all  the  laws,  the  magistrates,  and  the  police,  to  drive 
out  those  crimes  which  can  only  flourish  in  darkness.  The 
intimate  connection  between  physical  light  and  moral  and  intel- 
lectual light  and  progress  is  a  subject  well  worthy  of  an  exhaus- 
tive treatise. 

We  must,  however,  drop  the  general  subject  and  come  down 
to  our  particular  paraffine  lamp.  In  the  first  place,  this  is  the 
cheapest  light  that  has  ever  been  invented — cheaper  than  any 
kind  of  oil  lamp — cheaper  than  the  cheapest  and  nastiest  of 
candles,  and,  for  domestic  purposes,  cheaper  than  gas.  For 
large  warehouses,  shops,  streets,  public  buildings,  etc.  it  is 
not  so  cheap  as  gas  should  be,  but  is  considerably  cheaper  than 
gas  actually  is  at  the  price  extorted  by  the  despotism  of  com- 
mercial monopoly. 

The  reason  why  it  is  especially  cheaper  for  domestic  pur- 
poses is,  first,  because  the  small  consumer  of  gas  pays  a  higher 
price  than  the  large  consumer  ;  and  secondly,  because  a  lamp 
can  be  placed  on  a  table  or  wherever  else  its  light  is  required, 
and  therefore  a  small  lamp  flame  will  do  the  work  of  a  much 
larger  gas  flame.  We  must  remember  that  the  intensity  of 
light  varies  inversely  with  the  square  of  the  distance  from  the 
source  of  light ;  thus  the  amount  of  light  received  by  this  page 
from  a  flame  at  one  foot  distance  is  four  times  as  great  as  if  it 
were  two  feet  distant,  nine  times  as  great  as  at  three  feet,  six- 
teen times  as  great  as  at  four  feet,  one  hundred  times  as  great 
as  at  ten  feet,  and  so  on.  Hence  the  necessity  of  two  or  three 
great  flames  in  a  gas  chandelier  suspended  from  the  ceiling  of  a 
moderate-sized  room. 

In  a  sitting-room  lighted  thus  with  gas,  we  are  obliged,  in  order 
to  read  comfortably  by  the  distant  source  of  light,  to  burn  so 
much  gas  that  the  atmosphere  of  the  room  is  seriously  polluted 
by  the  products  of  this  extravagant  combustion.  A  lamp  at  a 
moderate  distance — say  eighteen  inches  or  two  feet,  or  there- 
abouts— will  enable  us  to  read  or  work  with  one  tenth  to  one- 
twentieth  the  amount  of  combustion,  and  therefore  with  so 
much  less  vitiation  of  the  atmosphere,  and,  if  we  use  a  paraffine 
lamp,  at  much  less  expense. 

But  the  chief  value  of  the  paraffine  lamp  is  felt  where  gas  is 
not  obtainable — in  the  country  mansion  or  villa,  the  farm- 


118  SCIENCE   Iff   SHORT   CHAPTERS. 

house,  and,  most  of  all,  in  the  poor  man's  cottage.  We  have 
Bible  Societies  for  providing  cheap  Bibles  ;  we  have  cheap 
standard  works,  cheap  magazines,  cheap  newspapers,  etc.;  but 
all  these  are  unavailable  to  the  poor  man  until  he  can  get  a 
good  and  cheap  light  wherewith  to  read  them  at  the  only  time 
he  has  for  reading  —  viz.  in  the  evenings,  when  his  work  is 
done.  One  shilling's  worth  of  cheap  literature  will  require 
two  shillings'  worth  of  dear  candles  to  supply  the  light  neces- 
sary for  reading  it.  Therefore,  the  cheapening  of  light  has 
quite  as  much  to  do  with  the  poor  man's  intellectual  progress 
as  the  cheapening  of  books  and  periodicals. 

For  a  man  to  read  comfortably,  and  his  wife  to  do  her 
needlework,  they  must  have  a  candle  for  each,  if  dependent 
on  tallow  dips.  They  may,  and  do,  struggle  on  with  one  such 
candle,  but  the  inconvenience  soon  sickens  them  of  their  occu- 
pation ;  the  man  lolls  out  for  an  idle  stroll,  soon  encounters  a 
far  more  bright  and  cheerful  room  than  the  gloomy  one  he  has 
just  left,  and,  moth-like,  he  is  attracted  by  the  light,  and 
finishes  up  his  evening  in  the  public-house. 

We  may  preach,  we  may  lecture,  we  may  coax,  wheedle,  or 
anathematize,  but  no  amount  of  words  of  any  kind  will  render 
a  gloomy,  ill-lighted  cottage  so  attractive  as  the  bright  bar  and 
tap-room  ;  and  human  nature,  irrespective  of  conventional  dis- 
tinctions of  rank  and  class,  always  seeks  cheerfulness  after  a 
day  of  monotonous  toil.  Fifty  years  ago  the  middle  classes 
were  accustomed  to  spend  their  evenings  in  taverns,  but  now 
they  prefer  their  homes,  simply  because  they  have  learned  to 
make  their  homes  more  comfortable  and  attractive. 

We  have  not  yet  learned  how  to  supply  the  working  millions 
with  suburban  villas,  but  if  their  small  rooms  can  be  made 
bright  and  cheerful  during  the  long  evenings,  a  most  important 
step  is  made  toward  that  general  improvement  of  social  habits 
which  necessarily  results  from  a  greater  love  of  home.  We 
may  safely  venture  to  predict  that  the  paraffine  lamp  will  have 
as  much  influence  in  elevating  the  domestic  character  of  the 
poorer  classes  as  the  street  lamps  have  had  in  purging  the 
streets  of  our  cities  from  the  crimes  of  darkness  that  once  in- 
fested them. 

A  great  deal  has  been  said  about  the  poisonous  character  of 
paraffine  works.  I  admit  that  they  have  much  to  answer  for  in 
reference  to  trout — that  the  clumsy  and  wasteful  management 
of  certain  ill-conducted  works  has  interfered  with  the  sport  of 
the  anglers  of  one  or  two  of  the  trout  streams  of  the  United 


ON   THE   SOCIAL   BENEFITS   OF   PARAFFINE.  119 

Kingdom — but  all  the  assertions  that  have  been  made  relative 
to  injury  to  human  health  are  quite  contrary  to  truth. 

The  fact  is  that  the  manufacture  of  mineral  oils  from  cannel 
and  shale  is  an  unusually  healthful  occupation.  The  men  cer- 
tainly have  dirty  faces,  but  are  curiously  exempt  from  those 
diseases  which  are  most  fatal  among  the  poor.  I  allude  to 
typhus  fever,  and  all  that  terrible  catalogue  of  ills  usually 
classed  under  the  head  of  zymotic  diseases.  This  has  been 
strikingly  illustrated  in  the  Flintshire  district.  The  very 
sudden  development  of  the  oil  trade  in  the  neighborhood  of 
Leeswood  caused  that  little  village  and  the  scattered  cottages 
around  to  be  crowded  to  an  extent  that  created  the  utmost 
alarm  among  all  who  are  familiar  with  the  results  of  such  over- 
crowding in  poor,  ill-drained,  and  ill-ventilated  cottages. 
Rooms  were  commonly  filled  with  lodgers  who  economized  the 
apartments  on  the  Box  and  Cox  principle,  the  night  workers 
sleeping  during  the  day,  and  the  day  workers  during  the  night, 
in  the  same  beds.  The  extent  to  which  this  overcrowding  was 
carried  in  many  instances  is  hardly  credible. 

Mr.  R.  Platt,  who  is  surgeon  to  most  of  the  collieries  and  oil- 
works  of  this  district,  reports  that  Leeswood  has  enjoyed  a 
singular  immunity  from  typhus  and  fever — that  during  a  period 
when  it  was  prevalent  as  a  serious  epidemic  among  the  agricult- 
ural population  living  on  the  slopes  of  the  surrounding  moun- 
tains, no  single  case  occurred  among  the  oil-making  population 
of  Leeswood,  though  its  position  and  overcrowding  seemed  so 
directly  to  court  its  visitation.  If  space  permitted,  I  might 
give  further  illustrations  in  reference  to  allied  diseases. 

There  is  no  difficulty  in  accounting  for  this.  Carbolic  acid, 
one  of  the  most  powerful  of  our  disinfectants,  is  abundantly 
produced  in  the  oil-works,  and  this  is  carried  by  the  clothes  of 
the  men,  and  with  the  fumes  of  the  oil  into  the  dwellings  of 
the  workmen  and  through  all  the  atmosphere  of  the  neighbor- 
hood, and  has  thereby  counteracted  some  of  the  most  deadly 
agencies  of  organic  poisons.  Besides  this,  the  paraffine  oil 
itself  is  a  good  disinfectant. 

Even  the  mischief  done  to  the  trout  is  more  than  counter- 
balanced by  the  destruction  of  those  mysterious  fungoid 
growths  which  result  from  the  admixture  of  sewage  matter  with 
the  water  of  oar  rivers,  and  are  so  destructive  to  human  health 
and  life.  The  carbolic  acid  and  paraffne  oil,  in  destroying 
these  as  well  as  the  trout,  are  really  acting  as  great  purifiers  of 
the  river,  so  that,  after  all,  the  only  interest  that  has  suffered  is 


120  SCIENCE   IN"   SHORT   CHAPTERS. 

the  spoiling  interest.  This  same  interest  has  otherwise  suffer- 
ed. The  old  haunts  of  the  snipe  and  woodcock,  of  partridges, 
hares,  and  pheasants,  are  being  ruthlessly  and  barbarously 
destroyed,  and  —  horrible  to  relate  —  hundreds  of  cottages, 
inhabited  by  vulgar,  hard-handed,  thick-booted  human  beings, 
are  taking  their  place.  Churches  are  being  extended,  school- 
houses  and  chapels  built  ;  penny  readings,  lectures,  concerts, 
etc.  are  in  active  operation,  and  even  drinking-fountains  are  in 
course  of  construction  ;  but  the  trout  have  suffered,  and  the 
woodcocks  are  gone. 

We  may  thus  measure  the  good  against  the  evil  as  it  stands 
here  in  the  head- quarters  of  oil-making,  and  should  add  to  one 
side  the  advantages  which  the  cheap  and  brilliant  light  affords 
— advantages  which  we  might  continue  to  enumerate,  but  they 
are  so  obvious  that  it  is  unnecessary  to  go  further. 

There  is  one  important  and  curious  matter  which  must  not 
be  omitted.  This,  like  the  moral  and  intellectual  advantages 
of  the  cheap  paraffine  light,  has  hitherto  remained  unnoticed — 
viz.  that  the  introduction  of  mineral  oils  and  solid  paraffine  for 
purposes  of  illumination  and  lubrication  has  largely  increased 
the  world's  supply  of  food. 

This  may  not  be  generally  obvious  at  first  sight  ;  but  to  him 
who,  like  the  writer,  has  had  many  a  supper  at  an  Italian 
osteria  with  peasants  and  carbonari,  it  is  obvious  enough.  He 
will  remember  how  often  he  has  seen  the  lamp  that  has  lighted 
himself  and  companions  to  their  supper  filled  from  the  same 
flask  as  supplied  the  salad  which  formed  so  important  a  part  of 
the  supper  itself.  Throughout  the  South  of  Europe  salads  are 
most  important  elements  of  national  food,  and  when  thus 
abundantly  eaten  the  oil  is  quite  necessary  ;  the  oil  is  also  used 
for  many  of  the  cookery  operations  where  butter  is  used  here, 
and  this  same  olive  oil  has  hitherto  been  the  chief,  and  in  some 
places  the  sole,  illuminating  agent.  The  poor  peasant  of  the 
South  looks  jealously  at  his  lamp,  and  feeds  it  stingily,  for  it 
consumes 'his  richest  and  choicest  food,  and,  if  well  supplied, 
would  eat  as  much  as  a  fair-sized  baby. 

The  Russian  peasant  and  other  Northern  people  have  a  simi- 
lar struggle  in  the  matter  of  tallow.  It  is  their  choicest  dainty, 
and  yet,  to  their  bitter  grief,  they  have  been  compelled  to  burn 
it.  Hundreds  and  thousands  of  tons  of  this  and  of  olive  oil 
have  been  annually  consumed  for  the  lubrication  of  our  steam 
engines  and  other  machines.  A  better  time  is  approaching 
now  that  paraffine  lamps  are  so  rapidly  becoming  the  chief 


01T  THE   SOCIAL  BENEFITS   OF   PARAFFINE.  121 

illuminators  of  the  whole  civilized  world,  superseding  the  crude 
tallow  candle  and  the  antique  olive-oil  lamp,  while,  at  the  same 
time,  the  tallow  candle  is  gradually  being  replaced  by  the 
beautiful  sperm-like  paraffine  candle  ;  and,  in  addition  to  this, 
the  greedy  engines  that  have  consumed  so  much  of  the  olive 
oil  and  the  tallow  are  learning  to  be  satisfied  with  lubricators 
made  from  minerals  kindred  to  themselves. 

The  peasants  of  the  sunny  South  will  feed  upon  salads  made 
doubly  unctuous  and  nutritious  by  the  abundant  oil  ;  their 
fried  meats,  their  pastry,  omelettes,  and  sauces  will  be  so 
much  richer  and  better  than  heretofore,  and  the  Russian  will 
enjoy  more  freely  his  well-beloved  and  necessary  tallow,  when 
the  candle  is  made  and  the  engine  lubricated  with  the  fat 
extracted  from  coals  and  stones  which  no  human  stomach  can 
envy.  I  might  travel  on  to  China  and  tell  of  the  work  that' 
paraffine  and  paraffine  oils  have  yet  to  do  among  the  many  mill- 
ions there  and  in  other  countries  of  the  East.  The  great  wave 
of  mineral  light  has  not  yet  fairly  broken  upon  their  shores  ; 
but  when  it  has  once  burst  through  the  outer  barriers,  it  will, 
without  doubt,  advance  with  great  rapidity,  and  with  an  influ- 
ence whose  beneficence  can  scarcely  be  exaggerated. 

(The  above  was  written  in  the  early  days  of  paraffine  lamps, 
and  while  the  writer  was  engaged  in  the  distillation  of  paraffine 
oils,  etc.  from  the  Leeswood  cannel.  These  are  now  practically 
superseded  by  American  petroleum  of  similar  composition,  but 
distilled  in  Nature's  oil-works.  The  anticipations  that  appeared 
Utopian  at  the  time  of  writing  have  since  been  fully  realized, 
or  even  exceeded,  as  the  wholesale  price  of  mineral  oil  has 
fallen  from  two  shillings  per  gallon  to  an  average  of  about 
eightpence,  and  lamps  have  been  greatly  improved.  At  this 
price  the  cost  of  maintaining  a  light  of  given  power  in  an  ordi- 
nary lamp  is  about  equal  to  that  of  ordinary  London  gas,  if  it 
were  supplied  at  one  shilling  per  thousand  cubic  feet.  The 
mineral  oil,  being  a  fine  hydrocarbon,  does  far  less  mischief 
than  gas  by  its  combustion,  as  may  be  proved  by  warming  a 
conservatory  with  a  paraffine  stove  and  another  with  a  gas  stove. 
In  the  latter  all  the  delicate  plants  will  be  killed  ;  in  the  first 
they  scarcely  suffer  at  all.  If  these  facts  were  generally  under- 
stood we  should  be  in~a  better  position  for  battle  with  the  gas 
monopolies.  The  importation  of  petroleum  to  the  United 
Kingdom  during  the  first  five  months  of  1882  amounted  to 
26,297,346  gallons.) 


CHAPTER  XVIII. 

THE    SOLIDITY    OF    THE    EARTH. 

IN  his  opening  address  to  the  Mathematical  and  Physical 
Section  of  the  British  Association,  Sir  William  Thomson 
affirmed,  "  with  almost  perfect  certainty,  that,  whatever  may 
be  the  relative  densities  of  rock,  solid  and  melted,  or  at  about 
the  temperature  of  liquefaction,  it  is,  I  think,  quite  certain  that 
cold  solid  rock  is  denser  than  hot  melted  rock  ;  and  no  possi- 
ble degree  of  rigidity  in  the  crust  could  prevent  it  from  break- 
ing in  pieces  and  sinking  wholly  below  the  liquid  lava,"  and 
that  "  this  process  must  go  on  until  the  sunk  portions  of  the 
crust  build  up  from  the  bottom  a  sufficiently  close-ribbed 
skeleton  or  frame,  to  allow  fresh  incrustations  to  remain  bridg- 
ing across  the  now  small  areas  of  lava-pools  or  lakes."* 

This  would  doubtless  be  the  case  if  the  material  of  the  earth 
were  chemically  homogeneous  or  of  equal  specific  gravity 
throughout,  and  if  it  were  chemically  inert  in  reference  to  its 
superficial  or  atmospheric  surroundings.  But  such  is  not  the 
case.  Ail  we  know  of  the  earth  shows  that  it  is  composed  of 
materials  of  varying  specific  gravities,  and  that  the  range  of 
this  variation  exceeds  that  which  is  due  to  the  difference 
between  the  theoretical  internal  heat  of  the  earth  and  its  actual 
surface  temperature. 

We  know  by  direct  experiment  that  these  materials,  when 
fused  together,  arrange  themselves  according  to  their  specific 
gravities,  with  the  slight  modification  due  to  their  mutual  diffusi- 
bilities.  If  we  take  a  mixture  of  the  solid  elements  of  which 
the  earth,  so  far  as  we  know  it,  is  composed,  fuse  them,  and 
leave  them  exposed  to  atmospheric  action,  what  will  occur  ? 

The  heavy  metals  will  sink,  the  heaviest  to  the  bottom,  the 
lighter  metals  (i.e.  those  that  we  call  the  metals  of  the  earth, 
because  they  form  the  basis  of  the  earth's  superficial  crust)  will 
rise  along  with  the  silicon,  etc.  to  the  surface  ;  these  and  the 
silicon  will  oxidize  and  combine,  forming  silicates,  and  a  suffi- 
cient supply  of  carbonic  acid  some  of  them,  such  as  calcium, 
magnesium,  etc.,  will  form  carbonates  when  the  temperature 
sinks  below  that  of  the  dissociation  of  such  compounds. 

*  Aafurr,  vol.  xir.  p,  429. 


THE  SOLIDITY  OF  THE  EARTH.  123 

The  scoria  thus  formed  will  float  upon  the  heavy  metals  below 
and  protect  them  from  cooling  by  resisting  their  radiation  ;  but 
if  in  the  course  of  contraction  of  this  crust  some  fissures  are 
formed  reaching  to  the  melted  metals  below,  the  pressure  of 
the  floating  solid  will  inject  the  fluid  metal  upward  into  these 
fissures  to  a  height  corresponding  to  the  flotation  depth  of  the 
solid,  and  thus  form  metallic  veins  permeating  the  lower  strata 
of  the  crust.  I  need  scarcely  add  that  this  would  rudely  but 
fairly  represent  what  we  know  of  the  earth. 

But  it  may  be  objected  that  I  only  describe  an  imaginary 
experiment.  This  is  true  as  regards  the  whole  of  the  materials 
united  in  a  single  fusion.  Nobody  has  yet  produced  a  com- 
plete model  with  platinum  and  gold  in  the  centre,  and  all  the 
other  metals  arranged  in  theoretical  order  with  the  oxidized, 
silicated,  and  carbonated  crust  outside  ;  but  with  a  limited 
number  of  elements  this  has  been  done,  is  being  done  daily, 
on  a  scale  of  sufficient  magnitude  to  amply  refute  Sir  William 
Thomson's  description  of  a  fused  earth  solidifying  from  the 
centre  outward. 

This  refutation  is  to  be  seen  in  our  blast  furnaces,  refining 
furnaces,  puddling  furnaces,  Bessemer  ladles,  steel-melting  pots, 
cupels,  foundry  crucibles  ;  in  fact,  in  almost  every  metallurgical 
operation  down  to  the  simple  fusion  of  lead  or  solder  in  a 
plumber's  ladle,  with  its  familiar  floating  crust  of  dross  or 
oxide. 

As  an  example,  I  will,  on  account  of  its  simplicity,  take 
the  open-hearth  refinery  and  the  refining  of  pig-iron.  Here  a 
metallic  mixture  of  iron,  silicon,  carbon,  sulphur,  etc.  is  sim- 
ply fused  and  exposed  to  the  superficial  action  of  atmospheric 
air.  What  is  the  result  ? 

Oxidation  of  the  more  oxidizable  constituents  takes  place, 
and  these  oxides  at  once  arrange  themselves  according  to  their 
specific  gravities.  The  oxidized  carbon  forms  atmospheric 
matter  and  rises  above  all  as  carbonic  acid  ;  then  the  oxidized 
silicon,  being  lighter  than  the  iron,  floats  above  that  and  com- 
bines with  aluminium  or  calcium  that  may  have  been  in  the  pig 
and  with  some  of  the  iron  ;  thus  forming  a  silicious  crust 
closely  resembling  the  predominating  material  of  the  earth's 
crust. 

When  the  oxidation  in  the  finery  is  carried  far  enough,  the 
melted  material  is  tapped  out  into  a  rectangular  basin  or 
mould,  usually  about  10  feet  long  and  about  3  feet  wide, 
where  it  settles  and  cools.  During  this  cooling  the  silica  and 


12-  fcCIEXCE   IX   SHORT   CHAPTE11S. 

silicates  —  i.e.  the  rock  matter  —  separate  from  tlie  metallic 
matter  and  solidify  on  the  surface  as  a  thin  crust,  which 
behaves  in  a  very  interesting-  and  instructive  manner.  At 
first  a  mere  skin  is  formed.  This  gradually  thickens,  and  as  it 
thickens  and  cools  becomes  corrugated  into  mountain  chains 
and  valleys  much  higher  and  deeper,  in  proportion  to  the  whole 
mass,  than  the  mountain  chains  and  valleys  of  our  planets. 
After  this  crust  has  thickened  to  a  certain  extent  volcanic 
action  commences.  Rifts,  dikes,  and  faults  are  formed  by  the 
shrinkage  of  the  metal  below,  and  streams  of  lava  are  ejected. 
Here  and  there  these  lava  streams  accumulate  around  their 
vent  and  form  isolated  conical  volcanic  mountains  with  decided 
craters,  from  which  the  eruption  continues  for  some  time. 
These  volcanoes  are  relatively  far  higher  than  Chimborazo. 
The  magnitude  of  these  actions  varies  with  the  quality  of  the 
pig-iron. 

The  open-hearth  finery  is  now  but  little  used,  but  probably 
some  are  to  be  seen  at  work  occasionally  in  the  neighborhood 
of  Glasgow,  and  I  am  sure  that  Sir  William  Thomson  will  find 
a  visit  to  one  of  them  very  interesting.  Failing  this,  he  may 
easily  make  an  experiment  by  tapping  into  agood-sized  "  cinder 
bogie"  some  melted  pig-iron  from  a  puddling  furnace  (taking 
it  just  before  the  iron  "comes  y>  nature''*),  and  leaving  the 
melted  mixture  to  cool  slowly  and  undisturbed. 

The  cinder  of  the  blast  furnace,  which  in  like  manner  floats 
on  the  top  of  the  melted  pig-iron,  resembles  still  more  closely 
the  prevailing  rock-matter  of  the  earth,  on  account  of  the  larger 
proportion,  and  the  varied  compounds,  of  earth-metals  it  con- 
tains. 

For  the  volcanic  phenomena  alone  he  need  simply  watch 
what  occurs  when  in  the  ordinary  course  of  puddling  the 
cinder  is  run  into  a  large  bogie,  and  the  bogie  is  left  to  cool 
standing  upright.  I  need  scarcely  add  that  these  phenomena 
strikingly  illustrate  and  confirm  Mr.  Mallett's  theory  of  earth- 
quakes, volcanoes,  and  mountain-formation. 

In  merely  passing  through  an  iron-making  district  one  may 
see  the  results  of  what  I  have  called  the  volcanic  action,  by 
simply  observing  the  form  of  those  oyster-shaped  or  cubical 
blocks  of  cinder  that  are  heaped  in  the  vicinity  of  every  blast 
furnace  that  has  been  at  work  for  any  time.  Radial  ridges  or 
consolidated  miniature  lava-streams  are  visible  on  the  exposed 
face  of  nearly  if  not  quite  all  of  these.  They  were  ejected  or 
squeezed  up  from  below  while  the  mass  was  cooling,  when  the 


ELECTRIC    LIGHTING.  125 

outer  crust  had  consolidated  but  the  inner  portion  still 
remained  liqaid.  Many  of  these  are  large  enough,  and  suffi- 
ciently well-marked,  to  be  visible  from  a  railway  carriage 
passing  a  cinder  heap  near  the  road.* 


CHAPTER  XIX. 

A    CONTRIBUTION    TO    THE    HISTORY    OF    ELECTRIC    LIGHTING. 

As  the  subject  of  lighting  by  electricity  is  occupying  so 
much  public  attention,  and  the  merits  of  various  inventors  and 
inventions  are  so  keenly  discussed,  the  following  facts  may  have 
some  historical  interest  in  connection  with  it. 

In  October,  1845,  I  was  consulted  by  some  American  gentle- 
men concerning  the  construction  of  a  large  voltaic  battery  for 
experimenting  upon  an  invention,  afterward  described  and 
published  in  the  specification  of  "  King's  Patent  Electric  Light" 
(Letters  Patent  granted  for  Scotland,  November  26th,  1845  ; 
enrolled  March  25th,  1840  ;  English  Patent  sealed  November 
4th,  1845). 

Mr.  King  was  not  the  inventor,  but  he  and  Mr.  Dorr  supplied 
capital,  and  Mr.  Snyder  also  held  a  share,  which  was  after- 
ward transferred  to  myself.  The  inventor  was  Mr.  Starr,  a 
young  man  about  twenty-five  years  of  age,  and  one  of  the 
ablest  experimental  investigators  with  whom  I  have  ever  had 
the  privilege  of  near  acquaintance. 

He  had  been  working  for  some  years  on  the  subject,  com- 
mencing with  the  ordinary  arc  between  charcoal  points.  His 
first  efforts  were  directed  to  maintaining  constancy,  and  he 
showed  me,  in  January  of  1846,  an  arrangement  by  which  he 
succeeded  in  effecting  an  automatic  renewal  of  contact  by 
means  of  an  electro-magnet,  the  armature  of  which  received 
the  electric  flow,  when  the  arc  was  broken,  and  which  thus 
magnetized  brought  the  carbons  together  and  then  allowed 
them  to  be  withdrawn  to  their  required  separation,  when  the 
flow  returned.  This  device  was  almost  identical  with  that 
subsequently  reinvented  and  patented  by  Mr.  Staite  (quite 

*  See  chapter  on  ' '  The  Origin  of  Lunar  Volcanoes. ' ' 


126  SCIENCE   IK   SHORT   CHAPTERS. 

independently,  I  believe),  and  which,  with  modifications,  has 
since  been  rather  extensively  used. 

Although  successful  so  far,  he  was  not  satisfied.  He  reasoned 
out  the  subject,  and  concluded  that  the  electric  spark  between 
metals,  the  electric  arc  between  the  carbons,  and  other  lumi- 
nous electric  phenomena  are  secondary  effects  due  to  the  heating 
and  illumination  of  electric  carriers  ;  that  the  electric  spark  of 
the  conductors  of  ordinary  electrical  machines  is  e-imply  a  trans- 
fer of  incandescent  particles  of  metal,  which  effect  a  kind  of 
electric  convection,  known  as  the  disruptive  discharge  ;  and 
that  the  more  brilliant  arc  between  the  carbon  points  is  simply 
due  to  the  use  of  a  substance  which  breaks  up  more  readily, 
and  gives  a  longer,  broader,  and  more  continuous  stream  of 
incandescent  convection  particles. 

This  is  now  readily  accepted,  but  at  that  time  was  only 
dawning  upon  the  understanding  of  electricians.  I  am  satis- 
fied that  Mr.  Starr  worked  out  the  principle  quite  originally. 
He  therefore  concluded  that,  the  light  being  due  to  solid  parti- 
cles heated  by  electric  disturbance,  it  would  be  more  advanta- 
geous— as  regards  steadiness,  economy,  and  simplicity — to 
place  in  the  current  a  continuous  solid  barrier,  which  should 
present  sufficient  resistance  to  its  passage  to  become  bodily 
incandescent  without  disruption. 

This  was  the  essence  of  the  invention  specified  in  King's 
Patent  as  "  a  communication  from  abroad,"  which  claims  the 
use  of  continuous  metallic  and  carbon  conductors,  intensely 
heated  by  the  passage  of  a  current  of  electricity,  for  the  pur- 
poses of  illumination. 

The  metal  selected  was  platinum,  which,  as  the  specification 
states,  "  though  not  so  infusible  as  iridiurn,  has  but  little  affin- 
ity for  oxygen,  and  offers  a  great  resistance  to  the  passage  of 
the  current. "  The  form  of  thin  sheets  known  by  the  name 
of  leaf -platinum  is  described  as  preferable.  These  to  be  rolled 
between  sheets  of  copper  in  order  to  secure  uniformity,  and  to 
be  carefully  cut  in  strips  of  equal  width,  and  with  a  clean  edge, 
in  order  that  one  part  may  not  be  fused  before  the  other  parts 
have  obtained  a  sufficiently  high  temperature  to  produce  a  brill- 
iant light.  This  strip  to  be  suspended  between  forceps. 

I  need  not  describe  the  arrangement  for  regulating  the  dis- 
tance between  the  forceps,  for  directing  the  current,  etc.,  as 
we  soon  learned  that  this  part  of  the  invention  was  of  no  prac- 
tical value,  on  account  of  the  narrow  margin  between  efficient 
incandescence  and  the  fusion  of  the  platinum.  The  experi- 


ELECTRIC   LIGHTING.  12 

ments  with  the  large  battery  that  I  made — consisting  of  100 
Daniell  cells,  with  two  square  feet  of  working  surface  of  each 
element  in  each  cell,  and  the  copper-plates  about  three  quarters 
of  an  inch  distant  from  the  zinc — satisfied  all  concerned  that 
neither  platinum  nor  any  available  alloy  of  platinum  and  iridinm 
could  be  relied  upon,  especially  when  the  grand  idea  of  sub- 
dividing the  light  by  interposing  several  platinum  strips  in  the 
same  circuit,  and  working  with  a  proportionally  high  power, 
was  carried  out. 

This  drove  Mr.  Starr  to  rely  upon  the  second  part  of  the 
specification — viz.  that  of  using  a  small  stick  of  carbon  made  in- 
candescent in  a  Torricellian  vacuum.  He  commenced  with  plum- 
bago, and,  after  trying  many  other  forms  of  carbon,  found  that 
which  lines  gas-retorts  that  have  been  long  in  use  to  be  the  best. 

The  carbon  stick  of  square  section,  about  one  tenth  of  an 
inch  thick  and  half  an  inch  working  length,  was  held  vertically, 
by  metallic  forceps,  at  each  end,  in  a  barometer  tube,  the 
upper  part  of  which,  containing  the  carbon,  was  enlarged  to  a 
sort  of  oblong  bulb.  A  thick  platinum  wire  from  the  upper 
forceps  was  sealed  into  the  top  of  the  tube  and  projected 
beyond  ;  a  similar  wire  passed  downward  from  the  lower  for- 
ceps, and  dipped  into  the  mercury  of  the  tube,  which  was  so 
long  that  when  arranged  as  a  barometer  the  enlarged  end  con- 
taining the  carbon  was  vacuous. 

Considerable  difficulty  was  at  first  encountered  in  supporting 
this  fragile  stick.  Metallic  supports  were  not  available,  on 
account  of  their  expansion  ;  and,  finally,  little  cylinders  of 
porcelain  were  used,  one  on  each  side  of  the  carbon  stick,  and 
about  three  eighths  of  an  inch  distant. 

By  connecting  the  mercury  cup  with  one  terminal  of  the 
battery,  and  the  upper  platinum  wire  with  the  other,  a  brilliant 
and  perfectly  steady  light  was  produced,  not  so  intense  as  the 
ordinary  disruption  arc  between  carbons,  but  equally  if  not 
more  effective,  on  account  of  the  magnitude  of  brilliant  radiat- 
ing, surface. 

Some  curious  phenomena  accompanied  this  illumination  of 
the  carbon.  The  mercury  column  fell  to  about  half  its  baro- 
metric height,  and  presently  the  glass  opposite  the  carbon 
stick  became  slightly  dimmed  by  the  deposition  of  a  thin  film 
of  sooty  deposit. 

At  first  the  depression  of  the  mercury  was  attributed  to  the 
formation  of  mercurial  vapor,  and  is  described  accordingly  in 
the  specification  ;  but  further  observation  refuted  this  theory, 


128  SCIENCE   1ST   SHORT   CHAPTERS. 

for  no  return  of  the  mercury  took  place  when  the  tube  was 
cooled.  The  depression  was  permanent.  The  formation  of 
vaporous  carbon  was  suggested  by  one  of  the  capitalists  ;  but 
neither  Mr.  Starr  nor  myself  was  satisfied  with  this,  nor  with 
any  other  surmise  we  were  able  to  make  during  Mr.  Starr's  life- 
time, nor  up  to  the  period  of  final  abandonment  of  the  enterprise. 

When  this  occurred  the  remaining  apparatus  was  assigned  to 
me,  and  I  retained  possession  of  the  finally  arranged  tube  and 
carbon  for  many  years,  and  have  shown  it  in  action  worked  by  a 
small  Grove's  battery  in  the  Town  Hall  of  Birmingham,  and  many 
times  to  my  pupils  at  the  Birmingham  and  Midland  Institute. 

These  exhibitions  suggested  an  explanation  of  the  mysterious 
gaseous  matter,  which  I  believe  to  be  the  correct  one,  and  also 
of  the  carbon  deposit.  It  is  this  :  That  the  carbon  contains 
occluded  oxygen  ;  that  when  the  carbon  is  heated  some  of  this 
oxygen  combines  with  the  carbon,  forming  carbonic  oxide  and 
carbonic  acid,  and  a  little  smoke.  I  proved  the  presence  of 
carbonic  acid  by  the  usual  tests,  but  did  not  quantitatively 
determine  its  proportion  of  the  total  atmosphere. 

If  I  were  fitting  up  another  tube  on  this  principle  I  should 
wash  it  with  a,  strong  solution  of  caustic  potash  before  filling 
with  mercury,  and  allow  some  of  the  potash  solution  to  float 
on  the  mercury  surface,  by  filling  the  tube  while  the  glass 
remained  moistened  with  the  solution.  My  object  would  be 
to  get  rid  of  the  carbonic  acid  as  soon  as  formed,  as  the  observa- 
tions I  have  made  lead  me  to  believe  that — when  the  carbon 
stick  is  incandescent  in  an  atmosphere  of  carbonic  acid  or  car- 
bonic oxide — a  certain  degree  of  dissociation  and  recombination 
is  continually  occurring,  which  weakens  and  would  ultimately 
break  up  the  carbon  stick,  and  increases  the  sooty  deposit. 

The  large  battery  was  arranged  for  intensity,  but  even  then 
it  was  found  that  the  quantity  (I  use  the  old-fashioned  terms) 
of  electricity  was  excessive,  and  that  it  worked  more  advanta- 
geously when  the  cells  were  but  partially  filled  with  acid  and 
sulphate.  A  larger  stick  of  carbon  might  have  been  used  with 
the  whole  surface  in  full  action. 

After  working  the  battery  in  various  ways,  and  duly  consid- 
ering the  merits  of  the  other  forms  of  battery  then  in  use,  Mr. 
Starr  was  driven  to  the  conclusion  that  for  the  purposes  of 
practical  illumination  the  voltaic  battery  is  a  hopeless  source  of 
power,  and  that  magneto-electric  machinery  driven  by  steam- 
power  must  be  used.  I  fully  concurred  with  him  in  this  con- 
clusion, so  did  Mr.  King,  Mr.  Dorr,  and  all  concerned. 


ELECTKIC    L1GHT1XO.  120 

Mr.  Starr  then  set  to  work  to  devise  a  suitable  dynamo-elec- 
tric machine,  and,  following  his  usual  course  of  starting  from 
first  principles,  concluded  that  all  the  armatures  hitherto  con- 
structed were  defective  in  one  fundamental  element  of  their 
arrangement.  The  thick  copper- wire  surrounding  the  soft  iron 
core  necessarily  follows  a  spiral  course,  like  that  of  a  coarse 
screw-thread  ;  bit  the  electric  current  or  lines  of  force,  which 
it  is  designed  to  pick  up  and  carry,  circulate  at  right  angles  to 
the  axis  of  the  core,  and  extend  to  some  distance  beyond  its 
surface.  The  problem  thus  presented  is  to  wind  around  the 
soft  iron  a  conductor  that  shall  be  broad  enough  to  grasp  a 
large  proportion  of  this  outspread  force,  and  yet  shall  follow  its 
course  as  nearly  as  possible  by  standing  out  at  right  angles  to 
the  axis  of  the  armature.  This  he  endeavored  to  effect  by 
using  a  core  of  square  section,  and  winding  round  it  a  broad 
ribbon  of  sheet  copper,  insulated  on  both  sides  by  cementing 
on  its  surfaces  a  layer  of  silk  ribbon.  This  armature  was  laid 
with  one  edge  against  one  side  of  the  core,  and  carried  on  thus 
to  the  angle  ;  then  turned  over  so  that  its  opposite  edge 
should  be  presented  to  the  next  side  of  the  core  ;  this  side  to 
be  followed  in  like  manner,  the  ribbon  similarly  turned  again 
at  the  next  corner,  and  so  on  till  the  core  became  fully  inclosed 
or  armed  with  the  continuous  ribbon,  which  thus  encircled  the 
core  with  its  edges  outward,  and  nearly  at  right  angles  to  the 
axis,  in  spite  of  its  width,  which  might  be  increased  to  any 
extent  found  by  experiment  to  be  desirable. 

At  this  stage  my  direct  co-operation  and  confidential  com- 
munication with  Mr.  Starr  ceased,  as  I  remained  in  London 
while  he  went  to  Birmingham  in  order  to  get  his  machinery 
constructed,  and  to  apply  it  at  the  works 'of  Messrs.  Elkington, 
who  had  then  recently  introduced  the  principle  of  dynamo- 
electric  motive-power  for  electro-plating,  etc.,  and  were,  I 
believe,  using  Woolrich's  apparatus,  the  patent  for  which  was 
dated  August  1st,  1842,  and  enrolled  February  1st,  1843. 

I  am  unable  to  state  the  results  of  his  efforts  in  Birmingham. 
I  only  heard  the  murmurs  of  the  capitalists,  who  loudly  com- 
plained of  expenditure  without  results.  They  had  dreamed  the 
same  dream  that  Mr.  Edison  has  recently  re-dreamed,  and  has 
told  the  world  so  loudly.  They  supposed  that  the  mechani- 
cally excited  current  might  be  carried  along  great  lengths  of 
wire,  and  the  carbons  interposed  wherever  required,  and  that 
the  same  electricity  would  flow  on  and  do  the  duty  of  illumina- 
tion over  and  over  again  as  a  river  may  fall  over  a  succession 


130  SCIENCE  D*  SHORT  CHAPTERS. 

of  weirs  and  turn  water-wheels  at  each.  Mr.  Starr  knew 
better  j  his  scepticism  was  misinterpreted  ;  he  was  taunted 
with  failure  and  non-fulfilment  of  the  anticipations  he  had 
raised,  and  with  the  fruitless  expenditure  of  large  sums  of 
other  people's  money.  He  was  a  high-minded,  honorable, 
and  very  sensitive  man,  suffering  already  from  overworked 
brain  before  he  went  to  Birmingham.  There  he  worked  again 
still  harder,  with  further  vexation  and  disappointment,  until 
one  morning  he  was  found  dead  in  his  bed.  Having,  during 
my  short  acquaintance  with  him,  enjoyed  his  full  confidence 
in  reference  to  all  his  investigations,  I  have  no  hesitation  in 
affirming  that  his  early  death  cut  short  the  career  of  one  who 
otherwise  would  have  largely  contributed  to  the  progress  of 
experimental  science,  and  have  done  honor  to  his  country. 

His  martyrdom,  for  such  it  was,  taught  me  a  useful  lesson  I 
then  much  needed — viz.  to  abstain  from  entering  upon  a  costly 
series  of  physical  investigations  without  being  well  assured  of 
the  means  of  completing  them,  and,  above  all,  of  being  able 
to  afford  to  fail. 

There  are  many  others  who  sorely  need  to  be  impressed  with 
the  same  lesson,  especially  at  this  moment  and  in  connection 
with  this  subject. 

The  warning  is  the  most  applicable  to  those  who  are  now 
misled  by  a  plausible  but  false  analogy.  They  look  at  the 
progress  made  in  other  things,  the  mighty  achievements  of 
modern  Science,  and  therefore  infer  that  the  electric  light — 
even  though  unsuccessful  hitherto — may  be  improved  up  to 
practical  success,  as  other  things  have  been.  A  great  fallacy 
is  hidden  here.  As  a  matter  of  fact,  the  progress  made  in 
electric  lighting  since  Mr.  Starr's  death,  in  1846,  has  been 
very  small  indeed.  As  regards  the  lamp  itself,  no  progress 
whatever  has  been  made.  I  am  satisfied  that  Starr's  continu- 
ous carbon  stick,  properly  managed  in  a  true  vacuum,  or  an 
atmosphere  free  from  oxygen,  carbonic  oxide,  carbonic  acid, 
or  other  oxygen  compound,  is  the  best  that  has  yet  been  placed 
before  the  public  for  all  purposes  where  exceptionally  intense 
illumination  (as  in  light-houses)  is  not  demanded.* 

*  The  burnt  card,  burned  bamboo,  and  other  flimsy  incandescent 
threads  now  (1882)  in  vogue,  merely  represent  Starr's  preliminary 
failures  prior  to  his  adoption  of  the  hard  adamantine  stick  of  retort- 
carbon,  which  I  suppose  will  be  duly  reinvented,  patented  again, 
and  form  the  basis  of  new  Limited  Companies,  when  the  present 
have  collapsed. 


ELECTRIC   LIGHTING.  131 

Comparing  electric  with  gas  lighting,  the  hopeful  believers 
in  progressive  improvement  appear  to  forget  that  gas-making 
and  gas-lighting  are  as  susceptible  of  further  improvement  as 
electric  lighting,  and  that,  as  a  matter  of  fact,  its  practical  prog- 
ress  during  the  last  forty  years  is  incomparably  greater  than 
that  of  the  electric  light.  I  refer  more  particularly  to  the 
practical  and  crucial  question  of  economy.  The  by-products, 
the  ammoniacal  salts,  the  liquid  hydrocarbons,  and  their 
derivatives,  have  been  developed  into  so  many  useful  forms  by 
the  achievements  of  modern  chemistry  that  these,  with  the 
coke,  are  of  sufficient  value  to  cover  the  whole  cost  of  manu- 
facture, and  leave  the  gas  itself  as  a  volatile  residuum  that  costs 
nothing.  It  would  actually  and  practically  cost  nothing,  and 
might  be  profitably  delivered  to  the  burners  of  gas  consumers 
(of  far  better  quality  than  now  supplied  in  London)  at  one 
shilling  per  thousand  cubic  feet,  if  gas- making  were  conduted 
on  sound  commercial  principles — that  is,  if  it  were  not  a  corpo- 
rate monopoly,  and  were  subject  to  the  wholesome  stimulating 
influence  of  free  competition  and  private  enterprise.  As  it  is, 
our  gas  and  the  price  we  pay  for  it  are  absurdities  ;  and  all 
calculations  respecting  the  comparative  cost  of  new  methods  of 
illumination  should  be  based  not  on  what  we  do  pay  per  candle- 
power  of  gas-light,  but  what  we  ought  to  pay  and  should  pay 
if  the  gas  companies  were  subjected  to  desirable  competition, 
or  visited  with  the  national  coniiscation  I  consider  they  deserve. 

Having  had  considerable  practical  experience  in  the  commer- 
cial distillation  of  coal  for  the  sake  of  its  liquid  and  solid 
hydrocarbons,  I  speak  thus  plainly  and  with  full  confidence. 

There  is  yet  another  consideration,  and  one  of  vital  impor- 
tance, to  be  taken  into  account — viz.  that,  whether  we  use  the 
electric  light  derived  from  a  dynamo-electric  source,  or  coal- 
gas,  our  primary  source  of  illuminating  power  is  coal,  or 
rather  the  chemical  energy  derivable  from  the  combination  of 
its  hydrogen  and  carbon  with  oxygen.  Now  this  chemical 
energy  is  a  limited  quantity,  and  the  progress  of  Science  can 
no  more  increase  this  quantity  than  it  can  make  a  ton  of  coal 
weigh  21  cvvts.  by  increasing  the  quantity  of  its  gravitating 
energy. 

The  demonstrable  limit  of  scientific  possibilities  is  the  eco- 
nomical application  of  this  limited  store  of  energy,  by  convert- 
ing it  into  the  demanded  form  of  force  without  waste.  The 
more  indirect  and  roundabout  the  method  of  application,  the 
greater  must  be  the  loss  of  power  in  the  course  of  its  transfer 


132  SCIENCE   IN   SHORT   CHAPTERS. 

and  conversion.  In  heating  tlie  boiler  that  sets  the  dynamo- 
electric  machine  to  work,  about  one  half  the  energy  of  the  coal 
is  wasted,  even  with  the  best  constructed  furnaces.  This 
merely  as  regards  the  quantity  of  water  evaporated.  In  con- 
verting the  heat-force  into  mechanical  power  —  raising  the 
piston,  etc.  of  the  steam-engine  —  this  working  half  is  again 
seriously  reduced.  In  further  converting -this  residuum  of 
mechanical  power  into  electrical  energy,  another  and  consider- 
able loss  is  suffered  in  originating  and  sustaining  the  motion  of 
the  dynamo-electric  machine,  in  the  dissipation  of  the  electric 
energy  that  the  armature  cannot  pick  up,  and  in  overcoming 
the  electrical  resistances  to  its  transfer. 

I  am  unable  to  state  the  amount  of  this  loss  in  trustworthy 
figures,  but  should  be  very  much  surprised  to  learn  that,  with 
the  best  arrangements  now  known,  more  than  one  tenth  of  the 
original  energy  of  the  coal  is  made  practically  available.  This 
small  illuminating  residuum  may,  and  doubtless  will,  be  in- 
creased by  the  progress  of  practical  improvement  ;  but,  from 
the  necessary  nature  of  the  problem,  the  power  available  for 
illumination  at  the  end  of  the  series  must  always  be  but  a  small 
portion  of  that  employed  at  the  beginning. 

In  burning  the  gas  derived  from  coal  we  obtain  its  illuminat- 
ing power  directly,  and  if  we  burn  it  properly  we  obtain  nearly 
all.  The  coke  residuum  is  also  directly  used  as  a  source  of 
heat.  The  chief  waste  of  the  original  energy  in  the  gas-works 
is  represented  by  that  portion  of  the  coke  that  is  burned  under 
the  retorts,  and  in  obtaining  the  relatively  small  amount  of 
steam-power  demanded  in  the  works.  These  are  far  more 
than  paid  for  by  the  value  of  the  liquid  hydrocarbons  and  the 
ammonia  salts,  when  they  are  properly  utilized. 

In  concluding  my  narrative  I  may  add  that  after  Mr.  Starr's 
death  the%  patentees  offered  to  engage  me  on  certain  terms  to 
carry  on  his  work.  I  declined  this,  simply  because  I  had  seen 
enough  to  convince  me  of  the  impossibility  of  any  success  at 
all  corresponding  to  their  anticipations.  During  the  interven- 
ing thirty  years  I  have  abstained  from  further  meddling  with 
the  electric  light,  because  all  that  I  had  seen  then,  and  had 
heard  of  since,  has  convinced  me  that — although  as  a  scientific 
achievement  the  electric  light  is  a  splendid  success — its  practi- 
cal application  to  all  purposes  where  cost  is  a  matter  of  serious 
consideration  is  hopeless,  and  must  of  necessity  continue  to 
be  so. 

Whoever  can  afford  to  pay  some  shillings  per  hour  for  a 


THE   FOKHATIOtf   OF   COAL. 


single  splendid  light  of  solar  completeness  can  have  it  without 
difficulty,  but  not  so  where  the  cost  in  pence  per  hour  per 
burner  has  to  be  counted. 

I  should  add  that  before  the  publication  of  King's  specifica- 
tion, Mr.  (now  Sir  William)  Grove  proposed  the  use  of  a  helix 
or  coil  of  platinum,  made  incandescent  by  electricity,  as  a  light 
to  be  used  for  certain  purposes.  This  was  shown  at  the  Royal 
Society  on  or  about  December  1st,  1845. 

Since  the  publication  of  the  above  in  1879,  I  have  learned, 
from  a  paper  in  the  Quarterly  Journal  of  Science,  by  Professor 
Ayrton,  that  in  1841  an  English  patent  was  granted  to  De 
Moylens  for  electric  lighting  by  incandescence. 


CHAPTER  XX. 

THE    FORMATION    OF    COAL. 

IN  the  course  of  a  pedestrian  excursion  made  in  the  summer 
of  1855  I  came  upon  the  Aachensee,  one  of  the  lakes  of  North 
Tyrol  rarely  visited  by  tourists.  It  is  situated  about  30  miles 
N.  E.  of  Innspruck,  and  fills  the  basin  of  a  deep  valley,  the 
upper  slopes  of  which  are  steep  and  richly  wooded.  The  water 
of  this  lake  is  remarkably  transparent  and  colorless.  With  one 
exception,  that  of  the  fountain  of  Cyane — a  deep  pool  forming 
the  source  of  the  little  Syracusan  river — it  is  the  most  trans- 
parent body  of  water  I  remember  to  have  seen.  This  trans- 
parency revealed  a  very  remarkable  sub-aqueous  landscape. 
The  bottom  of  the  lake  is  strewn  with  branches  and  trunks  of 
trees,  which  in  some  parts  are  in  almost  forest-like  profusion. 
As  I  was  alone  in  a  rather  solitary  region,  and  carrying  only  a 
satchel  of  luggage,  my  only  means  of  further  exploration  were 
those  afforded  by  swimming  and  diving.  Being  an  expert  in 
these,  and  the  July  summer  day  very  calm  and  hot,  I  remained 
a  long  time  in  the  water,  and,  by  swimming  very  carefully  to 
avoid  ripples,  was  able  to  survey  a  considerable  area  of  the 
interesting  scene  below. 

The  fact  which  struck  me  the  most  forcibly,  and  at  first 
appeared  surprising,  was  the  upright  position  of  many  of  the 
large,  trunks,  which  are  of  various  lengths  —  some  altogether 


134  SCIENCE   IN   SHORT   CHAPTERS. 

stripped  of  branches,  others  with  only  a  few  of  the  larger 
branches  remaining.  The  roots  of  all  these  are  more  or  less 
buried,  and  they  present  the  appearance  of  having  grown  where 
they  stand.  Other  trunks  were  leaning  at  various  angles  and 
partly  buried,  some  trunks  and  many  branches  lying  down. 

On  diving  I  found  the  bottom  to  consist  of  a  loamy  powder 
of  gray  color,  speckled  with  black  particles  of  vegetable  matter — 
thin  scaly  fragments  of  bark  and  leaves.  I  brought  up  several 
twigs  and  small  branches,  and  with  considerable  difficulty,  after 
a  succession  of  immersions,  succeeded  in  raising  a  branch 
about  as  thick  as  my  arm  and  about  eight  feet  long,  above 
three  fourths  of  which  was  buried,  and  only  the  end  above 
ground  in  the  water.  My  object  was  to  examine  the  condition 
of  the  buried  and  immersed  wood,  and  I  selected  this  as  the 
oldest  piece  I  could  reach. 

I  found  the  wood  very  dark,  the  bark  entirely  gone,  and  the 
annual  layers  curiously  loosened  and  separable  from  each  other, 
like  successive  rings  of  bark.  This  continued  till  I  had 
stripped  the  stick  to  about  half  of  its  original  thickness,  when 
it  became  too  compact  to  yield  to  further  stripping. 

This  structure  apparently  results  from  the  easy  decomposition 
of  the  remains  of  the  original  cambium  of  each  year,  and  may 
explain  the  curious  fact  that  so  many  specimens  of  fossilized 
wood  exhibit  the  original  structure  of  the  stem,  although  all 
the  vegetable  matter  has  been  displaced  by  mineral  substances. 
If  this  stem  had  been  immersed  in  water  capable  of  precipitat- 
ing or  depositing  mineral  matter  in  very  small  interstices,  the 
deposit  would  have  filled  up  the  vacant  spaces  between  these 
rings  of  wood  as  the  slow  decomposition  of  the  vegetable 
matter  proceeded.  At  a  later  period,  as  the  more  compact 
wood  became  decomposed,  it  would  be  substituted  by  a  further 
deposit,  and  thus  concentric  strata  would  be  formed,  present- 
ing a  mimic  counterpart  of  the  vegetable  structure. 

The  stick  examined  appeared  to  be  a  branch  of  oak,  and  was 
so  fully  saturated  with  water  that  it  sunk  rapidly  upon  being 
released. 

On  looking  around,  the  origin  of  this  sub-aqueous  forest  was 
obvious  enough.  Here  and  there  the  steep  wooded  slopes 
above  the  lake  were  broken  by  long  alleys  or  downward  strips 
of  denuded  ground,  where  storm  torrents,  or  some  such  agency, 
had  cleared  away  the  trees  and  swept  most  of  them  into  the 
lake.  A  few  uprooted  trees  lying  at  the  sides  of  these  bare 
alleys  told  the  story  plainly  enough.  Most  of  these  had  a 


THE   FORMATION   OF   COAL.  135 

considerable  quantity  of  earth  and  stones  adhering  to  their 
roots  :  this  explains  the  upright  position  of  the  trees  in  the 
lake. 

Such  trees  falling  into  water  of  sufficient  depth  to  enable 
them  to  turn  over  must  sink  root  downward,  or  float  in  an 
upright  position,  according  to  the  quantity  of  adhering  soil. 
The  difference  of  depth  would  tend  to  a  more  rapid  penetration 
of  water  in  the  lower  parts,  where  the  pressure  would  be 
greatest,  and  thus  the  upright  or  oblique  position  of  many  of 
the  floating  trunks  would  be  maintained  till  they  absorbed 
sufficient  water  to  sink  altogether. 

It  is  generally  assumed  that  fossil  trees  which  are  found  in 
an  upright  position  have  grown  on  the  spot  where  they  are 
found.  The  facts  I  have  stated  show  that  this  inference  is  by 
no  means  necessary,  not  even  when  the  roots  are  attached  and 
some  soil  is  found  among  them.  In  order  to  account  for  the 
other  surroundings  of  these  fossil  trees  a  very  violent  hypoth- 
esis is  commonly  made — viz.  that  the  soil  on  which  they  grew 
sunk  down  some  hundreds  of  feet  without  disturbing  them. 
This  demands  a  great  strain  upon  the  scientific  imagination, 
even  in  reference  to  the  few  cases  where  the  trees  stand  per- 
pendicular. As  the  majority  slope  considerably  the  difficulty 
is  still  greater.  I  shall  presently  show  how  trees  like  those 
immersed  in  Aachensee  may  have  become,  and  are  now  becom- 
ing, imbedded  in  rocks  similar  to  those  of  the  Coal  Measures. 

In  the  course  of  subsequent  excursions  on  the  fiords  of 
Norway  I  was  reminded  of  the  sub-aqueous  forests  of  the 
Aachensee,  and  of  the  paper  which  I  read  at  the  British  Asso- 
ciation meeting  of  1865,  of  which  the  above  is  an  abstract — 
not  by  again  seeing  such  a  deposit  under  water,  for  none  of 
the  fiords  approach  the  singular  transparency  of  the  lake,  but 
by  a  repetition  on  a  far  larger  scale  of  the  downward  strips  of 
denuded  forest-ground.  Here  in  Norway  their  magnitude 
justifies  me  in  describing  them  as  vegetable  avalanches.  They 
may  be  seen  on  the  Sognefjord,  and  especially  on  those 
terminal  branches  of  this  great  estuary,  of  which  the  steep  slopes 
are  well  wooded.  But  the  most  remarkable  display  that  I  have 
seen  was  in  the  course  of  the  magnificent,  and  now  easily  made, 
journey  up  the  Storfjord  and  its  extension  and  branches,  the 
Slyngsfjord,  Sunelvsfjord,  Nodalsfjord,  and  Geirangerfjord. 
Here  these  avalanches  of  trees,  with  their  accompaniment  of 
fragments  of  rock,  are  of  such  frequent  occurrence  that  sites  of 
the  farm-houses  are  commonly  selected  with  reference  to  possi- 


136  SCIENCE   IN    SHOUT   CHArTERS. 

ble  shelter  from  tlieir  ravages.  In  spite  of  tins  they  do  not  al- 
ways escape.  In  the  October  previous  to  my  last  visit  a  boat- 
house  and  boat  were  swept  away  ;  and  one  of  the  most  recent 
among  the  tracks  that  I  saw  reached  within  twenty  yards  of 
some  farm-buildings. 

What  has  become  of  the  millions  of  trees  that  are  thus 
falling,  and  have  fallen,  into  the  Norwegian  fiords  during  the 
whole  of  the  present  geological  era  ?  In  considering  this 
question  we  must  remember  that  the  mountain  slopes  forming 
the  banks  of  these  fiords  continue  downward  under  the  waters 
of  the  fiords  which  reach  to  depths  that  in  some  parts  are  to 
be  counted  in  thousands  of  feet. 

It  is  evident  that  the  loose  stony  and  earthy  matter  that 
accompanies  the  trees  will  speedily  sink  to  the  bottom  and  rest 
at  the  foot  of  the  slope  somewhat  like  an  ordinary  sub-aerial 
talus,  but  not  so  the  trees.  The  impetus  of  their  fall  must 
launch  them  afloat  and  impel  them  toward  the  middle  of  the 
estuary,  where  they  will  be  spread  about  and  continue  floating, 
until  by  saturation  they  become  dense  enough  to  sink.  They 
will  thus  be  pretty  evenly  distributed  over  the  bottom.  At  the 
middle  part  of  the  estuary  they  will  form  an  almost  purely 
vegetable  deposit,  mingled  only  with  the  very  small  portion  of 
mineral  matter  that  is  held  in  suspension  in  the  apparently  clear 
water.  This  mineral  matter  must  be  distributed  among  the 
vegetable  matter  in  the  form  of  impalpable  particles  having  a 
chemical  composition  similar  to  that  of  the  rocks  around. 
Near  the  shores  a  compound  deposit  must  be  formed  consisting 
of  trees  and  fragments  of  leaves,  twigs,  and  other  vegetable 
matter  mixed  with  larger  propoitions  of  the  mineral  debris. 

If  we  look  a  little  further  at  what  is  taking  place  in  the 
fiords  of  Norway  we  shall  see  how  this  vegetable  deposit  will 
ultimately  become  succeeded  by  an  overlying  mineral  deposit 
which  must  ultimately  conrtitute  a  stratified  rock. 

All  these  fiords  branch  up  into  inland  valleys  down  which 
pours  a  brawling  torrent  or  a  river  of  some  magnitude.  These 
are  more  or  less  turbid  with  glacier  mud  or  other  detritus,  and 
great  deposits  of  this  material  have  already  accumulated  in 
such  quantity  as  to  constitute  characteristic  modern  geologi- 
cal formations  bearing  the  specific  Norsk  name  of  oren,  as 
Laerdahoren,  Sundalsoren,  etc.,  describing  the  small  delta 
plains  at  the  mouth  of  the  river  where  it  enters  the  termination 
of  the  fiord,  and  which,  from  their  exceptional  fertility,  con- 
stitute small  agricultural  settlements  bearing  these  names, 


THE   FORMATION   OF   COAL.  1ST 

which  signify  the  river  sands  of  Laerdal,  Sundal,  etc.  These 
deposits  stretch  out  into  the  fiord,  forming  extensive  shallows 
that  are  steadily  growing  and  advancing  further  and  further 
into  the  fiord.  One  of  the  most  remarkable  examples  of  such 
deposits  is  that  brought  by  the  Storelv  (or  Justedals  Elv), 
which  flows  down  the  Justedal,  receiving  the  outpour  from  its 
glaciers,  and  terminates  at  Marifjoren.  When  bathing  here  I 
found  an  extensive  sub-aqueous  plain  stretching  fairly  across 
that  branch  of  the  Lyster  fiord  into  which  the  Storelv  flows. 
The  waters  of  the  fiord  are  whitened  to  a  distance  of  two  or 
three  miles  beyond  the  mouth  of  the  river.  These  deposits 
must,  if  the  present  conditions  last  long  enough,  finally  extend 
to  the  body,  and  even  to  the  mouth  of  the  fiords,  and  thus 
cover  the  whole  of  the  bottom  vegetable  bed  with  a  stratified 
rock  in  which  will  be  entombed,  and  well  preserved,  isolated 
specimens  of  the  trees  and  other  vegetable  forms  corresponding 
to  those  accumulated  in  a  thick  bed  below,  but  which  have 
been  lying  so  long  in  the  clear  waters  that  they  have  become 
soddened  into  homogeneous  vegetable  pulp  or  mud,  only 
requiring  the  pressure  of  solid  superstratum  to  convert  them 
into  coal. 

The  specimens  of  trees  in  the  upper  rock,  I  need  scarcely 
add,  would  be  derived  from  the  same  drifting  as  that  which 
produced  the  lower  pulp  ;  but  these  coming  into  the  water  at 
the  period  of  its  turbidity  and  of  the  rapid  deposition  of 
mineral  matter,  would  be  sealed  up  one  by  one  as  the  mineral 
particles  surrounding  it  subsided.  Fossils  of  estuarine  animals 
would,  of  course,  accompany  these,  or  of  fresh-water  animals 
where,  instead  of  a  fjord,  the  scene  of  these  proceedings  is  an 
inland  lake.  In  reference  to  this  I  may  state  that  at  the  inner 
extremities  of  the  larger  Norwegian  fiords  the  salinity  of  the 
water  is  so  slight  that  it  is  imperceptible  to  taste.  I  have  freely 
quenched  my  thirst  with  the  water  of  the  Sorfjord,  the  great 
inner  branch  of  the  Hardanger,  where  pallid  specimens  of 
bladder  wrack  were  growing  on  its  banks. 

In  the  foregoing  matter-of-fact  picture  of  what  is  proceed- 
ing on  a  small  scale  in  the  Aachensee,  and  on  a  larger  in 
Norway,  we  have,  1  think,  a  natural  history  of  the  formation, 
not  only  of  coal  seams,  but  also  of  the  Coal  Measures  around 
and  above  them. 

The  theory  which  attributed  our  coal  seams  to  such  vegetable 
accumulations  as  the  rafts  of  the  Mississippi  is  now  generally 
abandoned.  It  fails  to  account  for  the  state  of  preservation 


138  SCIENCE   IN   SHORT   CHAPTERS. 

and  the  position  of  many  of  the  vegetable  remains  associated 
with  coal. 

There  is  another  serious  objection  to  this  theory  that  I  have 
not  seen  expressed.  It  is  this  :  Rivers  bringing  down  to  their 
mouths  such  vegetable  deltas  as  are  supposed,  would  also  bring 
considerable  quantities  of  earthy  matter  in  suspension,  and  this 
would  be  deposited  with  the  trees.  Instead  of  the  2  or  3  per 
cent,  of  incombustible  ash  commonly  found  in  coal,  we  should 
thus  have  a  quantity  more  nearly  like  that  found  in  bituminous 
shales  which  may  thus  be  formed — viz.  from  20  to  80  per  cent. 

The  alternative  hypothesis  now  more  commonly  accepted — 
that  the  vegetation  of  our  coal-fields  actually  grew  where  we 
find  it — is  also  refuted  by  the  composition  of  coal-ash.  If  the 
coal  consisted  simply  of  the  vegetable  matter  of  buried  forests 
its  composition  should  correspond  to  that  of  the  ashes  of  plants  ; 
and  the  refuse  from  our  furnaces  and  fireplaces  would  be  a 
most  valuable  manure.  This  we  know  is  not  the  case. 
Ordinary  coal-ash,  as  Bischof  has  shown,  nearly  corresponds 
to  that  of  the  rocks  with  which  it  is  associated  ;  and  he  says 
that  "  the  conversion  of  vegetable  substances  into  coal  has  been 
effected  by  the  agency  of  water  ;"  and  also  that  coal  has  been 
formed,  not  from  dwarfish  mosses,  sedges,  and  other  plants 
which  now  contribute  to  the  growth  of  our  peat-bogs,  but 
from  the  stems  and  trunks  of  the  forest  trees  of  the  Car- 
boniferous Period,  such  as  Sigillarice  Lcpidodendra,  and 
Coniferce.*  All  we  know  of  these  plants  teaches  us  that  they 
could  not  grow  in  a  merely  vegetable  soil  containing  but  2  or  3 
per  cent,  of  mineral  matter.  Such  must  have  been  their  soil 
for  hundreds  of  generations  in  order  to  give  a  depth  sufficient 
for  the  formation  of  the  South  Staffordshire  10-yard  seam. 

All  these  and  other  difficulties  that  have  stood  so  long  in  the 
way  of  a  satisfactory  explanation  of  the  origin  of  coal  appear  to 
me  to  be  removed  if  we  suppose  that  during  the  Carboniferous 
Period  Britain  and  other  coal-bearing  countries  had  a  con- 
figuration similar  to  that  which  now  exists  in  Norway — viz. 
inland  valleys  terminating  in  marine  estuaries,  together  with 
inland  lake  basins.  If  to  this  we  superadd  the  warm  and 
humid  climate  usually  attributed  to  the  Carboniferous  Period, 
on  the  testimony  of  its  vegetable  fossils,  all  the  conditions 
requisite  for  producing  the  characteristic  deposits  of  the  Coal 
Measures  are  fulfilled. 

*  Hull,  "  On  the  Coal-fields  of  Great  Britain." 


THE   FORMATION"   OF   COAL.  139 

We  have  first  the  under-clay  due  to  the  beginning  of  this 
state  of  things,  during  which  the  hill  slopes  were  slowly 
acquiring  the  first  germs  of  subsequent  forest  life,  and  were 
nursing  them  in  their  scanty  youth.  This  deposit  would  be  a 
mineral  mud  with  a  few  fossils  and  that  fragmentary  or  fine 
deposit  of  vegetable  matter  that  darkens  the  carboniferous 
shales  and  stripes  the  sandstones.  Such  a  bed  of  dark  con- 
solidated mud,  or  fine  clay,  is  found  under  every  seam  of  coal, 
and  constitutes  the  "  floor"  of  the  coal-pit.  The  characteristic 
striped  rocks — the  "  linstey"  or  "  linsey"  of  the  Welsh  colliers 
— is  just  such  as  I  found  in  the  course  of  formation  in  the 
Aachensee  near  the  shore,  as  described  above. 

The  prevalence  of  estuarine  and  lacustrine  fossils  in  the  Coal 
Measures  is  also  in  accordance  with  this  :  the  constitution  of 
coal-ash  is  perfectly  so.  Its  extreme  softness  and  fineness  of 
structure  ;  its  chemical  resemblance  to  the  rocks  around,  and 
above,  and  below  ;  the  oblong  basin  form  common  to  our  coal- 
seams  ;  the  apparent  contradiction  of  such  total  destruction  of 
vegetable  structure  common  to  the  true  coal-seams,  while 
immediately  above  and  below  them  are  delicate  structures  well 
preserved,  is  explained  by  the  more  rapid  deposition  of  the 
latter,  and  the  slow  soddening  of  the  former  as  above 
described. 

I  do  not,  however,  offer  this  as  an  explanation  of  the  forma- 
tion of  every  kind  of  coal.  On  the  contrary,  I  am  satisfied  that 
cannel  coal,  and  the  black  shales  usually  associated  with  it, 
have  a  different  origin  from  that  of  the  ordinary  varieties  of 
bituminous  coal.  The  fact  that  the  products  of  distillation  of 
cannel  and  these  shales  form  different  series  of  hydrocarbons 
from  those  of  common  coal,  and  that  they  are  nearly  identical 
with  those  obtained  by  the  distillation  of  peat,  is  suggestive  of 
origin  in  peat-bogs,  or  something  analogous  to  them. 

To  the  above  I  may  add  the  concluding  sentences  of  the 
chapter  on  Coal  in  Ly ell's  **  Elements  of  Geology."  Speaking 
of  fossils  in  the  Coal  Measures,  he  says  :  "  The  rarity  of  air- 
breathers  is  a  very  remarkable  fact^when  we  reflect  that  our 
opportunities  of  examining  strata  in  close  connection  with  ancient 
land  exceed  in  this  case  all  that  we  enjoy  in  regard  to  any 
other  formations,  whether  primary,. secondary,  or  tertiary.  We 
have  ransacked  hundreds  of  soils  replete  with  the  fossil  roots 
of  trees  have  dug  out  hundreds  of  erect  trunks  and  stumps 
which  stood  in  the  position  in  which  they  grew,  have  broken 
up  myriads  of  cubic  feet  of  fuel  still  retaining  its  vegetable 


140  SCIENCE   IK   SHOUT   CHAPTERS. 

structure,  and,  after  all,  we  continue  almost  as  much  in  the 
dark  respecting  the  invertebrate  air-breathers  of  this  epoch,  as 
if  the  coal  had  been  thrown  down  in  mid-ocean.  The  early  date 
of  the  carboniferous  strata  cannot  explain  the  enigma,  because 
we  know  that  while  the  land  supported  a  luxuriant  vegetation, 
the  contemporaneous  seas  swarmed  with  life — with  Aiticulata, 
Mollusca,  Radiata,  and  Fishes.  We  must,  therefore,  collect 
more  facts  if  we  expect  to  solve  a  problem  which,  in  the 
present  state  of  science,  cannot  but  excite  our  wonder  ;  and  we 
must  remember  how  much  the  conditions  of  this  problem  have 
varied  within  the  last  twenty  years.  We  must  be  content  to 
impute  the  scantiness  of  our  data  and  our  present  perplexity 
partly  to  our  want  of  diligence  as  collectors,  and  paitly  to  our 
want  of  skill  as  interpreters.  We  must  also  confess  that  our 
ignorance  is  great  of  the  laws  which  govern  the  fossilization  of 
land  animals,  whether  of  low  or  high  degree." 

The  explanation  of  the  origin  of  coal  which  I  have  given  in 
the  foregoing  meets  all  these  difficulties.  It  shows  how  vast 
accumulations  of  vegetable  matter  may  have  been  formed  "  in 
close  connection  with  the  ancient  land,"  and  yet  "  as  if  the  coal 
had  been  thrown  down  in  mid-ocean"  as  far  as  the  remains  of 
terrestrial  animals  are  concerned.  It  explains  the  nearly  total 
absence  of  land  shells,  and  of  the  remains  of  other  animals  that 
must  have  lived  in  the  forests  producing  the  coal,  and  which 
would  have  been  buried  there  with  the  coal  had  it  been  formed 
on  land  as  usually  supposed.  It  also  meets  the  cases  of  the 
rare  and  curious  exceptions,  seeing  that  occasionally  a  land 
animal  would  here  and  there  be  drowned  in  such  liords  under 
circumstances  favorable  to  its  fossilization. 


CHAPTER  XXI. 

THE    SOLAR    ECLIPSE    OF    1871 THE    FIRST    TELEGRAMS. 

THIS  time  we  may  fairly  expect  some  approach  to  a  solution 
of  the  riddle  of  the  corona,  as  the  one  essential  which  neither 
scientific  skill  nor  Government  liberality  could  secure  to  the 
eclipse  observers,  has  been  afforded — viz.  fine  weather.  The 
telegraph  has  already  informed  us  of  this,  and  also  that  good 


THE   80LA.R  ECLIPSE   OF   1871.  141 

use  has  been  made  of  the  good  weather.  From  one  station 
we  arc  told  :  "  Thin  mist  ;  spectroscope  satisfactory  ;  rever- 
sion of  lines  entirely  confirmed  ;  six  good  photographs."  From 
another  :  "  Weather  line  ;  telescopic  and  camera  photographs 
successful  ;  ditto  polarization  ;  good  sketches  ;  many  bright 
lines  in  spectrum." 

This  is  very  different  from  the  gloomy  accounts  of  the- 
expedition  of  last  year  ;  when  we  consider  that  the  different 
observers  are  far  apart,  and  that  if  all  or  some  of  them  are 
similarly  favored  we  shall  have  in  the  photographs  a  series  of 
successive  pictures  taken  at  intervals  of  time  sufficiently  distant 
to  reveal  any  progressive  changes  that  may  have  occurred  in 
the  corona  while  the  moon's  shadow  was  passing  from  one 
station  to  the  other.  I  anticipate  some  curious  revelations 
from  these  progressive  photographs,  that  may  possibly  reconcile 
the  wide  differences  in  the  descriptions  that  competent  observ- 
ers have  given  of  the  corona  of  former  eclipses, which  they  had 
seen  at  stations  distant  from  each  other. 

Barely  two  years  have  elapsed  since  I  suggested,  in  "  The 
Fuel  of  the  Sun,"  that  the  great  solar  prominences  and  the 
corona  are  due  to  violent  explosions  of  the  dissociated  elements 
of  water  ;  that  the  prominences  are  the  gaseous  flashes,  and 
the  corona  the  ejected  scoria,  or  solidified  metallic  matter 
belched  forth  by  the  furious  cannonade  continually  in  progress 
over  the  greater  portion  of  the  solar  surface. 

This  explanation  at  first  appeared  extravagant,  especially  as 
it  was  carried  so  far  as  to  suggest  that  not  merely  the  corona, 
but  the  zodiacal  light,  the  zone  of  meteors  which  occasionally 
drop  showers  of  solid  matter  upon  the  earth,  and  even  the 
"  pocket  planets"  or  asteroids  so  irregularly  scattered  between 
the  orbits  of  Mars  and  Jupiter,  consist  of  solid  matter  thus 
ejected  by  the  great  solar  eruptions.  Even  up  to  the  spring  of 
the  present  year,  when  Mr.  Lockyer  and  other  leaders  of  the 
last  year's  expeditions  reported  their  imperfect  results,  and 
compared  them  with  various  theories,  this  one  was  not  thought 
worthy  of  their  attention. 

Since  that  time — during  the  past  six  or  eight  months — a 
change  has  taken  place  which  strikingly  illustrates  the  rapid 
progress  of  solar  discovery.  Observations  and  calculations  of 
the  force  and  velocity  of  particular  solar  eruptions  have  been 
made,  and  the  results  have  proved  that  they  are  amply  sufficient 
to  eject  solid  missiles  even  further  than  I  supposed  them  to  be 
carried. 


143  SCIENCE   IN   SHORT   CHAPTERS. 

Mr.  Proctor,  basing  his  calculations  upon  the  observations  of 
Respighi,  Zollner,  and  Professor  Young,  has  concluded  that  it 
is  even  possible  that  meteoric  matter  may  be  ejected  far  be- 
yond the  limits  of  our  solar  system  into  the  domain  of  the 
gravitation  of  other  stars,  and  that  other  stars  may  in  like  man- 
n°r  bombard  the  sun. 

This  appears  rather  startling  ;  but,  as  I  have  already  said, 
the  imagination  of  the  poet  and  the  novelist  is  beggared  by  the 
facts  revealed  by  the  microscope,  so  I  may  now  repeat  the 
assertion,  and  state  it  still  more  strongly,  in  reference  to  the 
revelations  of  the  telescope  and  the  spectroscope. 

As  a  sample  of  these,  I  take  the  observations  of  Professor 
Young,  made  on  September  7th  last,  and  described  fully  in 
Nature  on  October  19th. 

lie  first  observed  a  number  of  the  usual  flame-prominences 
having  the  typical  form  which  has  been  compared  to  a  **  ban- 
yan grove."  One  of  these  banyans  was  greater  than  the  rest. 
This  monarch  of  the  solar  flame-forest  measured  f fly -four 
thousand  miles  in  height,  and  its  outspreading  measured  in  one 
direction  about  07ie  hundred  thousand  miles.  It  was  a  large 
eruption-flame,  but  others  much  larger  have  been  observed,  and 
Professor  Young  would  probably  have  merely  noted  it  among 
the  rest,  had  not  something  further  occurred.  He  was  called 
away  for  twenty-five  minutes,  and  when  he  returned  *  the 
whole  thing  had  been  literally  blown  to  shreds  by  some  incon- 
ceivable uprush  from  beneath."  The  space  around  "was  filled 
with  flying  debris — a  mass  of  detached  vertical  fusiform  fila- 
ments, each  from  10"  to  30"  long  by  2"  or  3"  wide,  brighter 
and  closer  together  where  the  pillars  had  formerly  stood,  and 
rapidly  ascending."  Professor  Young  goes  on  to  say,  that 
"  When  I  first  looked,  some  of  them  had  already  reached  a 
height  of  100,000  miles,  and  while  I  watched  they  rose,  with 
a  motion  almost  perceptible  to  the  eye,  until  in  ten  minutes  the 
uppermost  were  200,000  miles  above  the  solar  surface.  This 
was  ascertained  by  careful  measurement." 

Here,  then,  we  have  an  observed  velocity  of  10,000  miles 
per  minute,  and  this  is  the  gaseous  matter,  merely  the  flash  of 
the  gun  by  which  the  particles  of  solidified  solar  matter  are 
supposed  to  be  projected. 

The  reader  must  pause  and  reflect,  in  order  to  form  an  ade- 
quate conception  of  the  magnitudes  here  treated — 100,000 
miles  long  and  54,000  miles  high  !  What  does  this  mean  ? 
Twelve  and  a  half  of  our  worlds  placed  side  by  side  to  measure 


THE   SOLAR   ECLIPSE   OF    1871.  143 

the  length,  und  six  and  three  quarters,  piled  upon  each  other, 
to  measure  the  height.  A  few  hundred  worlds  as  large  as  ours 
would  be  required  to  fill  up  the  whole  cubic  contents  of  this 
flame-cloud.  The  spectroscope  has  shown  that  these  promi- 
nences are  incandescent  hydrogen.  Most  of  my  readers  have 
probably  seen  a  soap-bubble  or  a  bladder  filled  with  the  sepa- 
rated elements  of  water,  and  then  exploded,  and  have  felt  the 
ringing  in  their  ears  that  has  followed  the  violent  detonation. 

Let  them  struggle  with  the  conception  of  such  a  bubble  or 
bladder  magnified  to  the  dimensions  of  only  one  such  a  world 
as  ours,  and  then  exploded  ;  let  them  strain  their  power  of 
imagination  even  to  the  splitting  point,  and  still  they  must  fall 
most  pitifully  to  picture  the  magnitude  of  this  solar  explosion 
observed  on  September  7th  last,  which  flashed  out  to  a  magni- 
tude of  more  than  five  hundred  worlds,  and  then  expanded  to 
the  size  of  more  than  five  thousand  worlds,  even  while  Profes- 
sor Young  was  watching  it.  Professor  Young  concludes  his 
description  by  stating  that  "  it  seems  far  from  impossible  that 
the  mysterious  coronal  streamers,  if  they  turn  out  to  be  truly 
solar,  as  now  seems  likely,  may  find  their  origin  and  explana- 
tion in  such  events.'' 

This,  and  a  number  of  similar  admissions,  suggestions,  and 
conclusions  from  the  leading  astronomers,  indicate  that  the 
eruption  theory  of  the  corona  will  not  be  passed  over  in  silence 
by  the  observers  of  this  eclipse,  and  it  is  to  this  that  I  have 
referred  in  the  above  remarks  respecting  the  interest  attaching 
to  a  series  of  photographs  showing  successive  states  of  this  out- 
spreading enigma. 

Father  Secchi's  spectroscopic  observations  on  the  uneclipsed 
sun  led  him  to  assert  the  existence  of  a  stratum  of  glowing 
metallic  vapors  immediately  below  the  envelope  connected  with 
the  hydrogen  of  the  eruptions.  This  is  just  what  is  required 
by  my  eruption  theory  to  supply  the  solid  materials  of  the 
ejections  forming  the  corona. 

Professor  Young's  announcement  of  the  reversal  of  the  spec- 
troscopic lines  at  the  moment  when  the  stratum  was  seen  inde- 
pendently of  the  general  solar  glare,  startled  Mr.  Lockyer  and 
others  who  had  disputed  the  accuracy  of  the  observations  of 
the  great  Italian  observer,  as  it  confirmed  them  so  completely. 
Scepticism  still  prevailed,  and  Young's  observation  was  ques- 
tioned ;  but  now  even  our  slender  telegraphic  communication 
from  Colonel  Tonnant  to  Dr.  Huggins  indicates  that  the  ques- 
tion must  be  no  longer  contested.  "  Reversion  of  lines  entirely 


144  SCIENCE   IN"   SHOET   CHAPTERS. 

confirmed  "  is  a  message  so  important  that  if  the  expeditions 
had  done  no  more  than  this,  all  their  cost  in  money  and  scien- 
tific labor  would  be  amply  repaid  in  the  estimation  of  those 
Mho  understand  the  value  of  pure  truth. 

A  few  more  fragments  of  intelligence  respecting  the  Eclipse 
Expedition  have  reached  us,  the  last  Indian  mail  having  started 
just  after  the  eclipse  occurred.  They  fully  confirm  the  first 
telegraphic  announcement,  rather  strengthening  than  otherwise 
the  expectations  of  important  results,  especially  in  reference  to 
the  photographs  of  the  corona. 

I  have  read  in  the  Ceylon  newspapers  some  full  descriptions 
by  amateur  observers,  in  which  the  general  magnificence  of  the 
phenomena  is  described.  From  these  it  is  evident  that  the 
corona  must  have  been  displayed  in  its  full  grandeur  ;  but  as 
the  writers  do  not  attempt  to  describe  those  features  which 
have  at  the  present  moment  a  special  scientific  interest,  I  shall 
not  dwell  upon  them,  but  await  the  publication  of  the  official 
report  of  the  chief,  and  of  the  more  important  collateral 
observing  expeditions. 

The  unsophisticated  reader  may  say,  "Are  not  one  man's 
eyes  as  good  as  another's,  and  why  should  the  observations  of 
the  learned  men  of  the  expeditions  be  so  much  better  than 
those  of  any  other  clear-sighted  persons  ?"  This  is  a  perfectly 
fair  question,  and  admits  of  a  ready  answer.  All  that  can  be 
known  by  mere  unprepared  naked  eye  observation  is  tolerably 
well  known  already  ;  the  questions  which  await  solution  can 
only  be  answered  by  putting  the  sun  to  torture  by  means  of 
instruments  specially  devised  for  that  purpose  ;  and  by  a  skil- 
ful organization,  and  division  of  labor  among  the  observers. 

There  is  so  much  to  be  seen  during  the  few  seconds  of  total 
obscuration  that  no  one  human  being,  however  well  trained  in 
the  art  of  observing,  could  possibly  see  all.  Therefore  it  is 
necessary  to  prearrange  each  observer's  part,  to  have  careful 
rehearsals  of  what  is  to  be  done  by  each  during  the  precious 
seconds  ;  and  each  man  must  exercise  a  vast  amount  of  self- 
control  in  order  to  confine  his  attention  to  his  own  particular 
bit  of  observation,  while  he  is  surrounded  with  such  marvellous 
phenomena  as  a  total  eclipse  presents. 

The  grandeur  of  the  gloomy  landscape,  the  sudden  starting 
out  of  the  greater  stars,  the  seeming  falling  of  the  vault  of 
heaven,  the  silence  of  the  animal  world,  the  closing  of  the 
flowers,  and  all  that  the  ordinary  observer  would  regard  with 
so  much  awe  and  wondering  delight,  must  be  sacrificed  by  the 


THE   SOLAB   ECLIPSE   OF   1871.  145 

philosopher,  whose  business  is  to  confine  his  gaze  to  a  narrow 
slit  between  two  strips  of  metal,  and  to  watch  nothing  else  but 
the  exact  position  and  appearance  of  a  few  bright  or  dark  lines 
across  what  appears  but  a  strip  of  colored  ribbon.  He  must 
resist  the  temptation  to  look  aside  and  around  with  the  stub- 
bornness and  self-denial  of  another  St.  Antonio.  Besides  this, 
he  must  thoroughly  understand  exactly  what  to  look  for,  and 
now  to  find  it.  By  combining  the  results  of  his  observations 
with  those  of  the  others,  who  in  like  manner  have  undertaken 
to  work  with  another  instrument,  or  upon  another  part  of  the 
phenomena,  we  get  a  scientific  result  comparable  to  that  which, 
in  a  manufactory,  we  obtain  by  the  division  of  labor  of  many 
skilled  workmen,  each  doing  only  that  which  by  his  training 
he  has  learned  to  do  the  best  and  the  most  expeditiously. 

FURTHER    DETAILS    BY    POST. 

Although  the  formal  official  reports  of  the  Eclipse  Expedi- 
tion are  not  yet  published,  and  may  not  be  for  some  weeks  or 
months,  we  are  able  from  the  letters  of  Lockyer,  Jannsen, 
Respighi,  Maclear,  etc.,  to  form  some  idea  of  the  general 
results.  We  may  already  regard  two  or  three  important 
questions  as  fairly  answered.  The  reversal  of  the  dark  solar 
lines  of  the  spectrum  which  was  first  announced  by  the  great 
Roman  observer,  Father  Secchi,  and  seen  by  him  without  an 
eclipse,  may  now  be  considered  as  established.  It  is  true  that 
all  the  observers  of  1871  did  not  witness  this.  Some  were  doubt- 
ful, but  others  observed  it  positively  and  distinctly. 

In  such  a  case  negative  results  do  not  refute  the  positive 
observations  of  qualified  men,  especially  when  several  of  such 
observations  have  been  made  independently  ;  the  phenomenon 
is  but  instantaneous,  a  mere  flash  of  bright  stripes  in  the  place 
of  dark  lines  across  the  colored  ribbon  of  the  spectroscope, 
which  happens  just  at  the  moment  before  and  after  totality, 
and  is  presented  only  when  the  instrument  is  accurately  direct- 
ed to  the  delicate  curved  vanishing  thread  of  light  which  is  the 
last  visible  fragment  of  the  solar  outline,  and  that  which  makes 
the  first  flash  of  his  reappearance. 

A  little  explanation  is  necessary  to  render  the  significance  of 
this  "  reversal  "  intelligible  to  those  who  have  not  specially 
studied  the  subject. 

1st.  When  the  spectroscope  is  directed  to  a  luminous  solid, 
a  simple  rainbow-band  or  u  continuous  spectrum"  is  seen. 
When,  on  the  other  hand,  the  object  is  a  luminous  gas  or 


146  SCIENCE   IK   SHORT   CHAPTERS. 

vapor  of  moderate  density,  the  spectrum  is  not  a  continuous 
band  with  its  colors  gradually  blending  ;  it  consists  only  of 
certain  luminous  stripes  with  blank  spaces  between  them,  each 
particular  gas  or'  vapor  showing  its  own  particular  set  of  stripes 
of  certain  colors,  and  always  appearing  at  exactly  the  same 
place,  so  invariably  and  certainly,  that,  by  means  of  such 
luminous  stripes,  the  composition  of  the  gas  or  vapor  may  be 
determined.  If,  however,  the  gas  be  much  compressed,  the 
stripes  widen  as  the  condensation  proceeds  ;  they  may  even 
spread  out  sufficiently  to  meet  and  form  a  continuous  spectrum 
like  that  from  a  solid.  Liquids  also  produce  continuous  spectra. 

2d.  When  a  luminous  solid  or  liquid,  or  very  dense  gas, 
capable  of  producing  a  continuous  spectrum,  is  viewed  through 
an  intervening  body  of  other  gas  or  vapor  of  moderate  or 
small  density,  fine  dark  lines  cross  the  spectrum  in  precisely 
the  same  places  as  the  bright  stripes  would  appear  if  this  inter- 
vening gas  or  vapor  were  luminous  and  seen  by  itself. 

When  the  spectroscope  is  directed  to  the  face  of  the  sun 
under  ordinary  circumstances,  it  presents  a  brilliant  continuous 
spectrum,  striped  with  a  multitude  of  the  dark  lines.  From 
this  it  has  been  inferred  that  the  luminous  face  of  the  sun  is 
that  of  an  incandescent  solid  or  liquid,  and  that  it  is  surround- 
ed by  the  gases  and  vapors  whose  bright  stripes,  when  artifi- 
cially produced,  occupy  precisely  the  same  places  as  the  dark 
lines  of  the  solar  spectrum.  This  was  the  theory  of  KirchhofE 
and  others  in  the  early  days  of  spectrum  analysis,  when  it  was 
only  known  that  solids  and  liquids  were  capable  of  producing 
a  continuous  spectrum.  The  important  discovery  that  gases 
and  vapors,  if  sufficiently  condensed,  will  also  produce  a  con- 
tinuous spectrum,  opened  another  speculation,  far  more  con- 
sistent with  the  other  known  facts  concerning  the  constitution 
of  the  sun — viz.  that  the  sun  may  be  a  great  gaseous  orb,  blaz- 
ing at  its  surface  and  gradually  increasing  in  density  from  the 
surface  toward  the  centre. 

According  to  this,  the  metals  sodium,  calcium,  barium, 
magnesium,  iron,  chromium,  nickel,  copper,  zinc,  strontium, 
cobalt,  manganese,  aluminium,  and  titanium,  whose  vapors, 
with  those  of  some  few  other  substances,  give  the  dark  lines 
that  cross  the  solar  spectrum,  should  exist  neither  as  solids  nor 
liquids  on  the  solar  surface,  but  as  blazing  gases.  But  such 
blazing  gases,  according  to  what  I  have  stated  above,  should 
give  us  bright  stripes  instead  of  dark  lines.  Why,  then,  are 
not  such  bright  stripes  seen  under  ordinary  circumstances  ? 


THE   SOLAR   ECLIPSE   OF   1871.  147 

This  is  easily  answered.  These  blazing  gases  must,  as  we 
proceed  from  the  surface  of  the  sun  downward,  become  so 
condensed  by  the  pressure  of  their  own  superincumbent  strata, 
as  to  produce  a  continuous  spectrum  of  great  brilliancy.  With 
such  a  background  the  bright  stripes  would  be  confounded  and 
lost  to  sight.  Besides  this,  the  outer  film  of  cooler  vapor 
through  which  our  vision  must  necessarily  penetrate  before 
reaching  the  luminous  solar  surface,  will  produce  the  dark  lines 
exactly  where  the  bright  stripes  should  be,  and  thus  effectually 
obliterate  them  ;  or,  in  other  words,  the  intervening  non-lumi- 
nous vapors  are  opaque  to  the  particular  rays  of  light  which  the 
bright  vapors  of  the  same  substance  emits. 

Therefore,  according  to  this  theory,  if  we  could  sweep  away 
these  outside  darkening  vapors,  and  screen  off  the  inner  layers 
of  denser  blazing  matter  which  produces  the  continuous  back- 
ground, we  should  have  a  spectrum  displaying  a  multitude  of 
bright  stripes  exactly  where  the  black  lines  of  the  ordinary 
solar  spectrum  appear. 

Secchi  announced  that  these  bright  lines  were  to  be  seen 
under  favorable  circumstances,  when,  by  skilful  management, 
the  rays  from  the  edge  of  the  sun  were  so  caught  by  the  slit  of 
the  spectroscope  as  to  exhibit  only  the  spectrum  of  the  super- 
ficial layer  of  the  sun's  bright  surface.  This  was  disputed  at 
the  time  by  Mr.  Lockyer,  who,  I  suspect,  omitted  to  consider 
the  atmospheric  difficulties  under  which  English  astronomers 
work,  and  the  fact  that  the  atmosphere  of  Italy  is  exceptionally 
favorable  for  delicate  astronomical  observation. 

If  he  had  fairly  considered  this  I  think  he  would  agree  with 
me  in  concluding  that  an  observation  of  this  kind,  avowedly 
made  with  great  difficulty  and  questionable  distinctness  by  so 
skilful  a  spectroscopic  observer  as  Father  Secchi,  could  not  pos- 
sibly be  seen  by  any  human  eyes  through  a  London  atmosphere. 

Subsequently  Professor  Young  startled  the  astronomical 
world  by  the  announcement  that,  at  the  moment  when  the 
thinnest  perceptible  thread  of  the  sun' s  edge  was  alone  display- 
ed during  the  eclipse  which  he  observed,  the  whole  of  the  dark 
lines  of  the  .solar  spectrum  flashed  out  as  bright  stripes  in  a 
most  unmistakable  manner.  This  observation  is  now  fully 
confirmed.  The  first  telegrams  from  Mr.  Pogson,  the  Govern- 
ment astronomer  of  Madras,  and  from  Colonel  Tennant,  both 
announce  this  most  positively,  Colonel  Tennant's  words  being, 
"  the  reversion  of  the  lines  fully  confirmed. "  A  similar  result 
was  obtained  by  some,  but  not  by  all,  of  the  Ceylon  observers. 


148  SCIENCE   LST   SHORT   CHAPTERS. 

To  understand  this  clearly,  we  must  consider  the  fact  that 
what  appears  to  us  as  the  outline  of  a  flat  disk  is  really  that 
part  of  the  sun  which  we  see  by  looking  horizontally  athwart 
his  rotundity,  just  as  we  look  at  the  ocean  surface  of  our  own 
earth  when  we  stand  upon  the  shore  and  see  its  horizon  out- 
line. When  the  moon  obscures  all  but  the  last  film  of  this 
solar  edge,  we  see  only  the  surface  of  the  supposed  gaseous 
orb,  just  that  portion  of  the  blazing  gases  which  are  not  greatly 
compressed  by  those  above  them,  and  which  accordingly 
should,  if  they  consist  of  the  vapors  or  the  gases  above  named, 
display  a  bright-striped  spectrum,  provided  the  intervening 
non-luminous  vapors  of  the  same  metals  are  not  sufficiently 
abundant  to  obscure  them — at  this  particular  moment,  when 
only  the  absolute  horizon-line  is  seen,  and  the  body  of  the 
moon  cuts  off  all  the  intervening  solar  surface,  and  the  lower 
or  denser  portion  of  the  intervening  super-solar  vapors,  though, 
of  course,  these  are  not  so  entirely  cut  off  as  the  continuous 
background. 

The  reversion  of  the  dark  lines  therefore  reveals  to  us  the 
stupendous  fact  that  the  surface  of  the  mighty  sun,  which  is  as 
big  as  a  million  and  a  quarter  of  our  worlds,  consists  of  a  flam- 
ing ocean  of  hydrogen  and  of  the  metals  above  named  in  a 
gaseous  condition,  similar  to  that  of  the  hydrogen  itself. 

This  fact,  coupled  with  the  other  revelations  of  the  spectro- 
scope, which,  without  the  help  of  an  eclipse,  reveals  the  surface 
outline  of  the  sun,  the  **  sierra''  and  the  "  prominences"  tell  us 
that  this  flaming  ocean  is  in  a  state  of  perpetual  tempest,  heav- 
ing up  its  billows,  and  flame-Alps  hundreds  and  thousands  of 
miles  in  height,  and  belching  forth  above  all  these  still  taller 
pillars  of  fire  that  even  reach  an  elevation  of  more  than  a 
hundred  thousand  miles,  and  then  burst  out  into  mighty  clouds 
of  flame  and  vapor,  bigger  than  five  hundred  worlds. 

What  does  the  last  eclipse  teach  us  in  reference  to  the 
corona  ?  Firstly  and  clearly,  that  Lockyei  's  explanation 
which  attributed  it  to  an  illumination  of  the  upper  legions  of 
the  earth's  atmosphere  must  be  now  forever  abandoned. 
This  theory  has  died  hard,  but,  in  spite  of  Mr.  Lockycr's 
proclamation  of  "victory  all  along  Hie  line,"  it  is  now  past 
galvanizing.  There  can  be  no  further  hesitation  in  pronouncing 
that  the  corona  actually  belongs  to  the  sun  itself,  that  it  is  a 
marvellous  solar  appendage  extending  from  the  sun  in  all 
directions,  but  by  no  means  regularly. 

The  immensity  of  this  appendage  will  be  best  understood  by 


THE   SOL  All    ECLIPSE    OF    1871.  149 

the  fact  that  the  space  included  within  the  outer  limits  of  the 
visible  corona  is  at  least  twenty  times  as  great  as  the  bulk  of 
the  sun  itself,  that  above  twenty-five  millions  of  our  worlds 
would  be  required  to  fill  it. 

Jannsen  says:  "I  believe  the  question  whether  the  corona 
is  due  to  the  terrestrial  atmosphere  is  settled,  and  we  have 
before  us  the  prospect  of  the  study  of  the  extra-solar  regions, 
which  will  be  very  interesting  and  fertile.'7 

The  spectroscope,  the  polariscope,  and  ordinary  vision  all 
concur  in  supporting  the  explanation  that  the  corona  is  com- 
posed of  solid  particles  and  gaseous  matter  intermingled.  It 
fulfils  exactly  all  the  requirements  of  the  hypothesis  which  at- 
tributes it  to  the  same  materials  as  those  which  in  a  gaseous 
state  cause  the  reversion  of  the  dark  lines  above  described,  but 
which  have  been  ejected  with  the  great  eruptions  forming  the 
solar  prominences,  and  have  become  condensed  into  glowing 
metallic  hailstones  as  their  distance  from  the  central  heat  has 
increased.  These  must  necessarily  be  accompanied  by  the 
vapors  of  the  more  volatile  materials,  and  should  give  out  some 
of  the  lighter  gases,  such  as  hydrogen,  which,  under  greater 
pressure,  would  be  occluded  within  them,  just  as  the  hydrogen 
gas  occluded  within  the  substance  of  the  Lenarto  meteor  (a 
mass  of  iron  which  fell  from  the  sky  upon  the  earth)  was 
extracted  by  the  late  Master  of  the  Mint  by  means  of  his 
mercurial  air-pump. 

The  rifts  or  gaps  between  the  radial  streamers,  which 
have  been  so  often  described  and  figured,  but  were  regarded 
by  some  as  optical  illusions,  are  now  established  as  unquestion- 
able facts.  Mr.  Lockyer,  the  last  to  be  convinced,  is  now 
compelled  to  admit  this,  which  overthrows  the  supposition  that 
this  solar  appendage  is  a  luminous  solar  atmosphere  of  any 
kind.  If  it  were  gaseous  or  true  vapor,  it  must  obey  the  law 
of  gaseous  diffusion,  and  could  not  present  the  phenomena  of 
bright  radial  streamers,  with  dark  spaces  between  them,  unless 
it  were  in  the  course  of  very  rapid  radial  motion  either  to  or 
from  the  sun. 

The  photographs  have  not  yet  been  published.  When  they 
have  all  arrived,  and  can  be  compared,  we  shall  learn  some- 
thing that  I  anticipate  will  be  extremely  interesting  respecting 
the  changes  of  the  corona,  as  they  have  been  taken  at  the 
different  stations  at  different  times.  I  alluded  to  this  subject 
before,  when  it  was  only  a  matter  of  possibility  that  such  a 
succession  of  pictures  might  have  been  taken.  We  now  have 


150  SCIENCE   IN   SHORT   CHAPTERS. 


the  assurance  that  such  pictures  have  been  obtained.  There 
can  be  no  question  about  optical  illusion  in  these  ;  they  are 
original  affidavits  made  by  the  corona  itself,  signed,  sealed, 
and  delivered  as  its  own  act  and  deed. 


CHAPTER  XXII. 

METEORIC    ASTRONOMY. 

THE  number  of  the  Quarterly  Journal  of  Science  for  May, 
1872,  contains  some  articles  of  considerable  interest.  The 
first  is  by  the  indefatigable  Mr.  Proctor,  on  "  Meteoric  Astron- 
omy," in  which  he  embodies  a  clear  and  popular  summary  of 
the  researches  which  have  earned  for  Signer  Schiaparelli  this 
year's  gold  medal  of  the  Astronomical  Society.  Like  all  who 
venture  upon  a  broad,  bold  effort  of  scientific  thought,  extend- 
ing at  all  into  the  regions  of  philosophical  theory,  Schiaparelli 
has  had  to  wait  for  recognition.  A  simple  and  merely 
mechanical  observation  of  a  bare  fact,  barely  and  mechanically 
recorded  without  the  exercise  of  any  other  of  the  intellectual 
faculties  than  the  external  senses  and  observing  powers,  is  at 
once  received  and  duly  honored  by  the  scientific  world  ;  but 
any  higher  effort  is  received  at  first  indifferently,  or  sceptically, 
and  is  only  accepted  after  a  period  of  probation,  directly  pro- 
portionate to  its  philosophical  magnitude  and  importance,  and 
inversely  proportionate  to  the  scientific  status  of  the  daring 
theorist. 

At  first  sight  this  appears  unjust :  it  looks  like  honoring  the 
laborers  who  merely  make  the  bricks,  and  despising  the  archi- 
tect who  constructs  the  edifice  of  philosophy  from  the  mate- 
rials they  provide.  Many  a  disappointed  dreamer,  finding 
that  his  theory  of  the  universe  has  not  been  accepted,  and  that 
the  expected  honors  have  not  been  showered  upon  him,  has 
violently  attacked  the  whole  scientific  community  as  a  con- 
temptible gang  of  low-minded  mechanical  plodders,  void  of 
imagination,  blind  to  all  poetic  aspirations,  and  incapable  of 
any  grand  and  comprehensive  flight  of  intellect. 

Had  these  impulsive  gentlemen  been  previously  subjected  to 
the  strict  discipline  of  inductive  scientific  training,  their  P9$i- 


METEORIC   ASTHONOM  V.  151 


tion  and  opinions  would  have  been  very  different.  Their 
great  theories  would  either  have  had  no  existence,  or  have  been 
much  smaller,  and  they  would  understand  that  philosophic 
caution  is  one  of  the  characteristic  results  of  scientific  train- 
ing- 
Simple  facts,  which  can  be  immediately  proved  by  simple 
experiments  and  simple  observations,  are  at  once  accepted,  and 
their  discoverers  duly  honored,  without  any  hesitation  or 
delay,  but  the  grander  efforts  of  generalization  require  careful 
thought  and  laborious  scrutiny  for  their  verification,  and  there- 
fore the  acknowledgment  of  their  merits  is  necessarily  delayed  ; 
but  when  it  does  arrive  full  justice  is  usually  done. 

Thus  Grove's  "  Correlation  of  the  Physical  Forces,"  the 
greatest  philosophical  work  on  purely  physical  science  of  this 
generation,  was  commenced  in  1842,  when  its  author  occupied 
but  a  humble  position  at  the  London  Institution.  The  book 
was  but  little  noticed  for  many  years,  and,  had  Mr.  Grove 
(now  Sir  William  Grove)  not  been  duly  educated  by  the  dis- 
cipline above  referred  to,  he  might  have  become  a  noisy  can- 
tankerous martyr,  one  of  those  "  Ill-used  men"  who  have 
been  made  familiar  to  so  many  audiences  by  Mr.  George 
Daw  son. 

Instead  of  this,  he  patiently  waited,  and,  as  we  have  lately 
seen,  the  well  -  deserved  honors  have  now  been  liberally 
awarded. 

In  a  very  few  years  hence  we  shall  be  able  to  say  the  same 
of  the  once  diabolical  Darwin,  and  eight  or  nine  other  theorists, 
who  must  all  be  content  to  take  their  trial  and  patiently  await 
the  verdict  ;  the  time  of  waiting  being  of  necessity  propor- 
tionate to  the  magnitude  of  the  issue. 

The  theories  of  Schiaparelli,  which,  as  Mr.  Proctor  says, 
"  after  the  usual  term  of  doubt  have  so  recently  received  the 
sanction  of  the  highest  astronomical  tribunal  of  Great  Britain," 
are  not  of  so  purely  speculative  a  character  as  to  demand  a 
very  long  "term  of  doubt."  They  are  directly  based  on 
observations  and  mathematical  calculations  which  bring  them 
under  the  domain  of  the  recognized  logic  of  mathematical  prob- 
ability. Those  who  arc  specially  interested  in  the  modern 
progress  of  astronomy  should  read  this  article  in  the  Quarterly 
Journal  of  Science,  which  is  illustrated  with  the  diagrams 
necessary  for  the  comprehension  of  the  researches  and  reason- 
ing of  Schiaparelli  and  others  who  have  worked  on  the  same 
ground. 


T5S  SCIENCE   IN   SHORT   CHAPTERS. 

I  can  only  state  the  general  results,  which  are  that  the 
meteors  which  we  see  every  year,  more  or  less  abundantly,  on 
the  nights  of  the  10th  and  llth  of  August,  and  which  always 
appear  to  come  from  the  same  point  in  the  heavens,  are  then 
and  thus  visible  because  they  form  part  of  an  eccentric  ellipti- 
cal zone  of  meteoric  bodies  which  girdle  the  domain  of  the 
sun  ;  and  that  our  earth,  in  the  course  of  its  annual  journey 
round  the  sun,  crosses  and  plunges  more  or  less  deeply  into 
this  ellipse  of  small  attendant  bodies,  which  are  supposed  to  be 
moving  in  regular  orbits  around  the  sun. 

Schiaparelli  has  compared  the  position,  the  direction,  and 
the  velocity  of  motion  of  the  August  meteors  with  the  orbit  of 
the  great  comet  of  1862,  and  infers  that  there  is  a  close  con- 
nection between  them,  so  close  that  the  meteors  may  be 
regarded  as  a  sort  of  trail  which  the  comet  has  left  behind. 
He  does  not  exactly  say  that  they  are  detached  vertebra)  of 
the  comet's  tail,  but  suggests  the  possibility  of  their  original 
connection  with  its  head. 

Similar  observations  have  been  made  upon  the  November 
meteoric  showers,  which,  by  similar  reasoning,  are  associated 
with  another  comet  ;  and  further  yet,  it  is  assumed  upon  anal- 
ogy that  other  recognized  meteor  systems,  amounting  to 
nearly  two  hundred  in  number,  are  in  like  manner  associated 
with  other  comets. 

If  these  theories  are  sound,  our  diagrams  and  mental  pict- 
ures of  the  solar  system  must  be  materially  modified.  Besides 
the  central  sun,  the  eight  planets,  and  the  asteroids  moving  in 
their  nearly  circular  orbits,  and  some  eccentric  comets  travel- 
ling in  long  ellipses,  we  must  add  a  countless  multitude  of 
small  bodies  clustered  in  elliptical  rings,  all  travelling  together 
in  the  path  marked  by  their  containing  girdle,  and  following 
the  lead  of  a  streaming  vaporous  monster,  their  parent  comet. 

We  must  count  such  comets,  and  such  rings  filled  with 
attendant  fragments,  not  merely  by  tens  or  hundreds,  but  by 
thousands  and  tens  of  thousands,  even  by  millions  ;  the  path 
of  the  earth  being  but  a  thread  in  space,  and  yet  a  hundred  or 
two  are  strung  upon  it. 

In  this  article  Mr.  Proctor  seems  strongly  disposed  to  return 
to  the  theory  which  attributes  solar  heat  and  light  to  a  bom- 
bardment of  meteors  from  without,  and  the  solar  corona  and 
zodiacal  light  as  visible  presentments  of  these  meteors.  Still, 
however,  ho  clings  to  the  more  recent  explanation  which 
regards  the  corona,  the  zodiacal  light,  and  the  meteors  as 


METE01UC   ASTKOXOAIY.  153 

matter  ejected  from  the  sun  by  the  same  forces  as  those  pro- 
ducing the  solar  prominences.  For  my  own  part  I  shall  not  be 
at  all  surprised  if  we  find  that,  ere  long,  these  two  apparently 
conflicting  hypotheses  are  fully  reconciled. 

The  progress  of  solar  discovery  has  been  so  great  since  Janu- 
ary, 1870,  when  my  ejection  theory  was  published,  that  I  may 
now  carry  it  out  much  further  than  I  then  dared,  or  was  justi- 
fied in  daring,  to  venture.  Actual  measurement  of  the  pro- 
jectile forces  displayed  in  some  of  the  larger  prominences 
renders  it  not  merely  possible,  but  even  very  probable,  that 
some  of  the  exceptionally  great  eruptive  efforts  of  the  sun  may 
be  sufficiently  powerful  to  eject  solar  material  beyond  the 
reclaiming  reach  of  his  own  gravitating  power. 

In  such  a  case  the  banished  matter  must  go  on  wandering 
through  the  boundless  profundity  of  space  until  it  reaches  the 
domain  of  some  other  sun,  which  will  clutch  the  fragment  with 
its  gravitating  energies,  and  turn  its  straight  and  ever-onward 
course  into  a  curved  orbit.  Thus  the  truant  morsel  from  our 
sun  will  become  the  subject  of  another  sun — a  portion  of 
another  solar  sytem. 

What  one  sun  may  do,  another  and  every  other  may  do  like- 
wise, and,  if  so,  there  must  be  a  mutual  bombardment,  a 
ceaseless  interchange  of  matter  between  the  countless  suns  of 
the  universe.  This  is  a  startling  view  of  our  cosmical  rela- 
tions, but  we  are  driving  rapidly  toward  a  general  recognition 
of  it. 

The  November  star  showers  have  perpetrated  some  irregu- 
larities this  year.  They  have  been  very  unpunctual,  and  have 
not  come  from  their  right  place.  We  have  heard  something 
from  Italy,  but  not  the  tidings  of  the  Leonides  that  were 
expected.  Instead  of  the  great  display  of  the  month  occurring 
on  the  13th  and  14th,  it  was  seen  on  the  27th.  We  have 
accounts  from  different  parts  of  England,  Ireland,  Scotland, 
and  Wales,  also  from  Italy,  Greece,  Egypt,  etc. 

Mr.  Slinto,  in  a  letter  to  the  Times,  estimates  the  number 
seen  at  Suez  as  reaching  at  least  30,000,  while  in  Italy  and 
Athens  about  200  per  minute  were  observed.  They  were  not, 
however,  the  Leonides — that  is,  they  did  not  radiate  from  a 
point  in  the  constellation  Leo,  but  from  the  region  of  Andro- 
meda. Therefore  they  were  distinct  from  that  system  of 
small  wanderers  usually  designated  the  "  November  meteors," 
were  not  connected  with  Tempel's  comet  (comet  1,  1866), 
but  belong  to  quite  another  set. 


154  SCIENCE   IK   SHORT   CHAPTERS. 

The  question  now  discussed  by  astronomers  is  whether  they 
are  connected  with  any  other  comet,  and,  if  so,  with  which 
comet  ? 

In  the  Monthly  Notices  of  the  Royal  Astronomical  Society, 
published  October  24th  last,  is  a  very  interesting  paper  by 
Professor  Herschel,  on  "  Observations  of  Meteor  Showers," 
supposed  to  be  connected  with  "  JBiela's  comet,"  in  which  he 
recommends  that  "  a  watch  should  be  kept  during  the  last 
week  in  November  and  the  first  week  in  December,"  in  order 
to  verify  "  the  ingenious  suggestions  of  Dr.  Weiss,"  which, 
popularly  stated,  amount  to  this — viz.  that  a  meteoric  cloud 
is  revolving  in  the  same  orbit  as  Biela's  comet,  and  that  in 
1772  the  earth  dashed  through  this  meteoric  orbit  on  Decem- 
ber 10th.  In  1826  it  did  the  same,  on  December  4th  ;  in 
1852  the  earth  passed  through  the  node  on  November  28th, 
and  there  are  reasons  for  expecting  a  repetition  at  about  the 
same  date  in  1872. 

The  magnificent  display  of  the  27th  has  afforded  an  impor- 
tant verification  of  these  anticipations  which  become  especially 
interesting  in  connection  with  the  curious  history  of  Biela's 
comet,  which  receives  its  name  from  M.  Biela,  of  Joseph- 
stadt,  who  observed  it  in  1826,  calculated  its  orbit,  and  con- 
sidered it  identical  with  the  comets  of  1772,  1805,  etc.  It 
travels  in  a  long  eccentric  ellipse,  and  completes  its  orbit  in 
2410  days — about  6f  years.  It  appeared  again,  as  predicted, 
in  1832  and  1846. 

Its  orbit  very  nearly  intersects  that  of  the  earth,  and  thus 
affords  a  remote  possibility  of  that  sort  of  collision  which  has 
excited  so  much  terror  in  the  minds  of  many  people,  but 
which  an  enthusiastic  astronomer  of  the  present  generation 
would  anticipate  with  something  like  the  sensational  interest 
which  stirs  the  soul  of  a  London  street-boy  when  he  is  madly 
struggling  to  keep  pace  with  a  fire-engine. 

The  calculations  for  1832  showed  that  this  comet  should 
cross  the  earth's  orbit  a  little  before  the  time  of  the  earth's 
arrival  at  the  same  place  ;  but  as  such  a  comet,  travelling  in 
such  an  orbit,  is  liable  to  possible  retardations,  the  calculations 
could  only  be  approximately  accurate,  and  thus  the  sensational 
astronomer  was  not  altogether  without  hope.  This  time,  how- 
ever, he  was  disappointed  ;  the  comet  was  punctual,  and  cross- 
ed the  critical  node  about  a  month  before  the  earth  reached  it. 

As  though  to  compensate  for  this  disappointment,  the 
comet  at  its  next  appearance  exhibited  some  entirely  new 


METEOJEUC    ASTRONOMY.  155 

phenomena.  It  split  itself  into  two  comets,  in  such  a  manner 
that  the  performance  was  visible  to  the  telescopic  observer. 
Both  of  these  comets  had  nuclei  and  short  tails,  and  they 
alternately  varied  in  brightness,  sometimes  one,  then  the 
other,  having  the  advantage.  They  travelled  on  at  a  distance 
of  about  156,000  miles  from  each  other,  with  parallel  tails, 
and  with  a  sort  of  friendly  communication  in  the  form  of  a 
faint  arc  of  light,  which  extended,  as  a  kind  of  bridge,  from 
one  to  the  other.  Besides  this,  the  one  which  was  first  the 
brighter,  then  the  fainter,  and  finally  the  brighter  again,  threw 
out  two  additional  tails,  one  of  which  extended  lovingly 
towards  its  companion. 

The  time  of  return  in  1852  was,  of  course,  anxiously 
expected  by  astronomers,  and  careful  watch  was  kept  for  the 
wanderers.  They  came  again  at  the  calculated  time,  still 
separated  as  before. 

They  were  again  due  in  1859,  in  1866,  and,  finally,  at 
about  the  end  of  last  November,  or  the  beginning  of  the  pres- 
ent month.  Though  eagerly  looked  for  by  astronomers  in  all 
parts  of  the  civilized  world,  they  have  been  seen  no  more  since 
1852. 

What,,  then,  has  become  of  them  ?  Have  they  further  sub- 
divided ?  Have  they  crumbled  into  meteoric  dust  ?  Have 
they  blazed  or  boiled  into  thin  air  ?  or  have  they  been  dragged 
by  some  interfering  gravitation  into  another  orbit  ?  The  last 
supposition  is  the  most  improbable,  as  none  of  the  visible 
inhabitants  of  space  have  come  near  enough  to  disturb  them. 

The  possibility  of  a  dissolution  into  smaller  fragments  is 
suggested  by  the  fact  that,  instead  of  the  original  single 
comet,  or  the  two  fragments,  meteoric  showers  have  fallen 
toward  the  earth  at  the  time  when  it  has  crossed  the  orbit  of 
the  original  comet,  and  these  showers  have  radiated  from  that 
part  of  the  heavens  in  which  the  comet  should  have  appeared. 
Such  was  the  case  with  the  magnificent  display  of  November 
27th,  and  astronomers  arc  inclining  more  and  more  to  the  idea 
that  comets  and  meteors  have  a  common  origin — that  meteors 
are  little  comets,  or  comets  are  big  meteors. 

In  the  latest  of  the  Monthly  Notices  of  the  Royal  Astronom- 
ical Society,  published  last  week,  is  a  paper  by  Mr.  Proctor, 
in  which  he  expands  the  theory  expounded  three  years  ago  by 
an  author  whom  your  correspondent's  modesty  prevents  him 
from  naming — viz.  that  the  larger  planets — Jupiter,  Saturn, 
Uranus,  and  Neptuae  —  are  minor  suns,  ejecting  meteoric 


156  SCIENCE   IN   SHORT   CHAPTERS. 

matter  from  them  by  the  operation  of  forces  similar  to  those 
producing  the  solar  prominences. 

Mr.  Proctor  subjects  this  bold  hypothesis  to  mathematical 
examination,  and  finds  that  the  orbit  of  Tempel's  comet  and 
its  companion  meteors  correspond  to  that  which  would  result 
from  such  an  eruption  occurring  on  the  planet  Uranus.  An 
eruptive  force  effecting  a  velocity  of  about  thirteen  miles  per 
second,  which  is  vastly  smaller  than  the  actually  measured 
velocity  of  the  matter  of  the  solar  eruptions,  would  be  suffi- 
cient to  thrust  such  meteoric  or  cometary  matter  beyond  the 
reclaiming  reach  of  the  gravitation  of  Uranus,  and  hand  it 
over  to  the  sun,  to  make  just  such  an  orbit  as  that  of  TernpeFs 
comet  and  the  Leonides  meteors. 

He  shows  that  other  comets  and  meteoric  zones  are  similarly 
allied  to  other  planets,  and  thus  it  may  be  that  the  falling  stars 
and  comets  are  fragments  of  Jupiter,  Saturn,  Uranus,  or 
Neptune.  Verily,  if  an  astronomer  of  the  last  generation 
were  to  start  up  among  us  now,  he  would  be  astounded  at 
modern  presumption. 

The  star  shower  of  November  27th,  and  its  connection  with 
Bicla's  broken  and  lost  comet,  referred  to  in  my  last  letter,  are 
still  subjects  of  research  and  speculation.  On  November  30th 
Professor  Klinkerfues  sent  to  Mr.  Pogson,  of  the  Madras 
Observatory,  the  following  startling  telegram  :  "  Biela  touch- 
ed earth  on  27th.  Search  near  Theta  Centauri." 

Mr.  Pogson  searched  accordingly  from  comet-rise  to  sunrise 
on  the  two  following  mornings,  but  in  vain  ;  for  even  in  India 
they  have  had  cloudy  weather  of  late.  On  the  third  day, 
however,  he  had  "  better  luck,"  saw  something  like  a  comet 
through  an  opening  between  clouds,  and  on  the  following  days 
was  enabled  to  deliberately  verify  this  observation  and  deter- 
mine the  position  and  some  elements  of  the  motion  of  the 
comet,  which  displayed  a  bright  nucleus,  and  faint  but  distinct 
tail. 

This  discovery  is  rather  remarkable  in  connection  with  the 
theoretical  anticipation  of  Professor  Klinkerfues  ;  but  the  con- 
clusion directly  suggested  is  by  no  means  admitted  by  astron- 
omers. Some  have  supposed  that  it  is  not  the  primary  Biela, 
but  the  secondary  comet,  or  offshoot,  which  grazed  the  earth, 
and  was  seen  by  Mr.  Pogson  ;  others  that  it  was  neither  the 
body,  the  envelope,  nor  the  tail  of  either  of  the  comets  which 
formed  the  star  shower,  but  that  the  meteors  of  November 
27th  were  merely  a  trail  which  the  comet  left  behind. 


THE    "GREAT   ICE   AGE.'*  157 

A  multitude  of  letters  were  read  at  the  last  and  previous 
meeting  of  the  Astronomical  Society,  in  which  the  writers 
described  the  details  of  their  own  observations.  As  these 
letters  came  from  nearly  all  parts  of  the  world,  the  data  have 
an  unusual  degree  of  completeness,  and  show  very  strikingly 
the  value  of  the  work  of  amateur  astronomical  observers. 

By  the  collation  and  comparison  of  these,  important  induc- 
tions are  obtainable.  Thus,  Professor  A.  S.  Ilerschel  concludes 
that  the  earth  passed  through  seven  strata  of  meteoric  bodies, 
having  each  a  thickness  of  about  50,000  miles — in  all  about 
350,000  miles.  As  the  diameter  of  the  visible  nebulosity  of 
Biela's  comet  was  but  40,000  miles  when  nearest  the  earth  in 
1832,  the  great  thickness  of  these  strata  indicates  something 
beyond  the  comet  itself. 

Besides  this,  Mr.  Hind's  calculation  for  the  return  of  the 
primary  comet  shows  that  on  November  2*7th  it  was  250 
millions  of  miles  from  the  earth. 

Those,  however,  who  are  determined  to  enjoy  the  sensation 
of  supposing  that  they  really  have  been  brushed  by  the  tail  of 
a  comet,  still  have  the  secondary  comet  to  fall  back  -upon. 
This,  as  already  described,  was  broken  off  the  original,  from 
which  it  was  seen  gradually  to  diverge,  but  was  still  linked  to 
it  by  an  arch  of  nebulous  matter. 

If  this  divergence  has  continued,  it  must  now  be  far  distant 
— sufficiently  far  to  afford  me  an  opportunity  of  safely  adding 
another  to  the  numerous  speculations — viz.  that  we  may,  on 
November  2Yth,  have  plunged  obliquely  through  this  connect- 
ing arm  of  nebulous  matter,  which  was  seen  stretching 
between  the  parent  cornet  and  its  offshoot.  The  actual  posi- 
tion of  the  meteoric  strata  above  referred  to  is  quite  consistent 
with  this  hypothesis. 


CHAPTER   XXIII. 

THE    "  GREAT    ICE    AGE"    AND    THE    ORIGIN    OF    THE    "TILL." 

THE  growth  of  science  is  becoming  so  overwhelming  that  the 
old  subdivisions  of  human  knowledge  are  no  longer  sufficient 
for  the  purpose  of  dividing  the  labor  of  experts.  It  is  scarcely 
possible  now  for  any  man  to  become  a  naturalist,  a  chemist,  or 
a  physicist  in  the  full  sense  of  either  term  ;  he  must,  if  he 


158  SCIENCE   Itf   SHORT   CHAPTERS. 

aims  at  thoroughness,  be  satisfied  with  a  general  knowledge  of 
the  great  body  of  science,  and  a  special  and  full  acquaintance 
with  only  one  or  two  of  its  minor  subdivisions.  Thus  geology, 
though  but  a  branch  of  natural  history,  and  the  youngest  of  its 
branches,  has  now  become  so  extensive  that  its  ablest  votaries 
are  compelled  to  devote  their  best  efforts  to  the  study  of  sec- 
tions which  but  a  few  years  ago  were  scarcely  definable. 

Glaciation  is  one  of  these,  which  now  demands  its  own  ele- 
mentary text-books  over  and  above  the  monographs  of  original 
investigators.  This  demand  has  been  well  supplied  by  Mr. 
James  Geikie  in  "  The  Great  Ice  Age,"  *  of  which  a  second 
edition  has  just  been  issued.  Every  student  of  glacial  phe- 
nomena owes  to  Mr.  Geikie  a  heavy  debt  of  gratitude  for  the 
invaluable  collection  of  facts  and  philosophy  which  this  work 
presents.  It  may  now  be  fairly  described  as  a  standard  treatise 
on  the  subject  which  it  treats. 

One  leading  feature  of  the  work  offers  a  very  aggressive  in- 
vitation to  criticism.  Scotchmen  are  commonly  accused  of 
looking  upon  the  whole  universe  through  Scotch  spectacles,  and 
here  we  have  a  Scotchman  treating  a  subject  which  affects  near- 
ly the  whole  of  the  globe,  and  devoting  about  half  of  his  book 
to  the  details  of  Scottish  glacial  deposits  ;  while  England  has 
but  one  third  of  the  space  allowed  to  Scotland,  Ireland  but 
a  thirtieth,  Scandinavia  less  than  a  tenth,  North  America  a 
sixth,  and  so  on  with  the  rest  of  the  world.  Disproportionate 
as  this  may  appear  at  first  glance,  further  acquaintance  with  the 
work  justifies  the  pre-eminence  which  Mr.  Geikie  gives  to  the 
Scotch  glacial  deposits.  Excepting  Norway,  there  is  no  coun- 
try in  Europe  which  affords  so  fine  a  field  for  the  study  of  the 
vestiges  of  extinct  glaciers  as  Scotland,  and  Scotland  has  an 
advantage  even  over  Norway  in  being  much  better  known  in 
geological  detail.  Besides  this,  we  must  always  permit  the 
expounder  of  any  subject  to  select  his  own  typical  illustrations, 
and  welcome  his  ability  to  find  them  in  a  region  which  he  him- 
self has  directly  explored. 

Mr.  Geikie's  connection  with  the  Geological  Survey  of  Scot- 
land has  afforded  him  special  facilities  for  making  good  use  of 
Scottish  typical  material,  and  he  has  turned  these  opportunities 
to  such  excellent  account  that  no  student  after  reading  **  The 
Great  Ice  Age"  will  find  fault  with  its  decided  nationality. 

*  "  The  Great  Ice  Age,  and  its  Relation  to  the  Antiquity  of  Man." 
By  James  Geikie,  F.  B.  S.,  &c.  Second  edition,  revised,  1877.  Daldy 
and  Isbister. 


THE    "GREAT   ICE   AGE."  159 

The  leading  feature — the  basis,  in  fact — of  this  work  deserves 
especial  notice,  as  it  gives  it  a  peculiar  and  timely  value  of  its 
own.  This  feature  is  that  the  subject — as  compared  with  its 
usual  treatment  by  other  leading  writers — is  turned  round  and 
presented,  so  to  speak,  bottom  upward.  De  Saussure,  Char- 
pentier,  Agassiz,  Humboldt,  Forbes,  Hopkins,  Whewell,  Stark, 
Tyndall,  etc.  have  studied  the  living  glaciers,  and  upon  the 
data  thus  obtained  have  identified  the  work  of  extinct  glaciers. 
Chronologically  speaking,  they  have  proceeded  backward,  a 
method  absolutely  necessary  in  the  early  stages  of  the  inquiry, 
and  which  has  yielded  admirable  results.  Geikie,  in  the  work 
before  us,  proceeds  exactly  in  the  opposite  order.  Availing 
himself  of  th^  means  of  identifying  glacial  deposits  which  the 
retrogressive  method  affords,  he  plunges  at  once  to  the  lowest 
and  oldest  of  these  deposits,  which  he  presents  the  most  prom- 
inently, and  then  works  upward  and  onward  to  recent  glacia- 
tion. 

The  best  illustration  I  can  offer  of  the  timely  advantage  of 
this  reversed  treatment  is  (with  due  apology  for  necessary 
egotism)  to  state  my  own  case.  In  1841,  when  the  "  glacial 
hypothesis,"  as  it  was  then  called,  was  in  its  infancy,  Professor 
Jamieson,  although  very  old  and  nearly  at  the  end  of  his 
career,  took  up  the  subject  with  great  enthusiasm,  and  devoted 
to  it  a  rather  disproportionate  number  of  lectures  during  his 
course  on  Natural  History.  Like  many  of  his  pupils,  I  became 
infected  by  his  enthusiasm,  and  went  from  Edinburgh  to  Switz- 
erland, where  I  had  the  good  fortune  to  find  Agassiz  and  his 
merry  men  at  the  "  Hotel  des  Neufchatelois" — two  tents  raised 
upon  a  magnificent  boulder  floating  on  the  upper  part  of  the 
Aar  glacier.  After  a  short  but  very  active  sojourn  there  I 
"  did,"  not  without  physical  danger,  many  other  glaciers  in 
Switzerland  and  the  Tyrol,  and  afterward  practically  studied 
the  subject  in  Norway,  North  Wales,  and  wherever  else  an 
opportunity  offered,  reading  in  the  mean  time  much  of  its  spe- 
cial literature  ;  but,  like  many  others,  confining  my  reading 
chiefly  to  authors  who  start  with  living  glaciers  and  describe 
their  doings  most  prominently.  When,  however,  I  read  the 
first  edition  of  Mr.  Geikie's  "Great  Ice  Age,"  immediately 
after  its  publication,  his  mode  of  presenting  the  phenomena, 
bottom  upward,  suggested  a  number  of  reflections  that  had 
never  occurred  before,  leading  to  other  than  the  usual  explana- 
tions of  many  glacial  phenomena,  and  correcting  some  errors 
into  which  I  had  fallen  in  searching  for  the  vestiges  of  ancient 


160  SCIENCE   IN   SHORT   CHAPTE11S. 


glaciers.  As  these  suggestions  and  corrections  may  be  inter- 
esting to  others,  as  they  have  been  to  myself,  I  will  here  state 
them  in  outline. 

The  most  prominent  and  puzzling  reflection  or  conclusion 
suggested  by  reading  Mr.  Geikie's  description  of  the  glacial 
deposits  of  Scotland  was,  that  the  great  bulk  of  them  are  quite 
different  from  the  deposits  of  existing  glaciers.  This  reminded 
me  of  a  previous  puzzle  and  disappointment  that  I  had  met  in 
Norway,  where  I  had  observed  such  abundance  of  striation, 
such  universality  of  polished  rocks  and  rounded  mountains,  and 
so  many  striking  examples  of  perched  blocks,  with  scarcely  any 
decent  vestiges  of  moraines.  This  was  especially  the  case  in 
Arctic  Norway.  Coasting  from  Trondhjem  to  Hammerfest, 
winding  round  glaciated  islands,  in  and  out  of  fiords  banked 
with  glaciated  rock-slopes,  along  more  than  a  thousand  miles 
of  shore  line,  displaying  the  outlets  of  a  thousand  ancient 
glacier  valleys,  scanning  eagerly  throughout  from  sea  to  sum- 
mit, landing  at  several  stations,  and  climbing  the  most  com- 
manding hills,  I  saw  only  one  ancient  moraine — that  at  the  Ox- 
fjord. station  described  in  "  Through  Norway  with  Ladies."  * 

*  The  terminal  moraine  at  the  Oxfjord  station,  which  I  have  al- 
ready mentioned  as  the  only  ancient  example  of  an  ordinary  moraine 
that  I  have  seen  in  Arctic  Norway,  was,  of  course,  a  special  object  of 
interest  to  me.  Further  observation  showed  that  it  does  not  merely 
consist  of  the  heap  of  stones  I  noticed  in  1856,  which  appears  like  a 
disturbed  talus  cut  through,  and  heaped  up  at  its  lower  part,  but 
that  there  is  another  moraine  adjoining  it,  or  in  continuation  with  it, 
which  is  covered  with  vegetation,  and  stretches  quite  across  the 
mouth  of  the  valley.  The  Duke  of  Roxburgh,  who  is  well  acquainted 
with  this  neighborhood,  having  spent  sixteen  summers  in  Arctic 
Norway,  was  one  of  our  fellow-passengers,  and  told  me  that  this 
moraine  forms  a  barrier  that  dams  up  the  waters  of  a  considerable 
lake,  abounding  with  remarkably  fine  char.  I  learned  this  just  as  the 
packet  was  starting,  too  late  to  go  on  shore  even  for  a  few  minutes, 
and  obtain  a  view  of  this  lake  and  the  valley  beyond.  This  I  regret, 
as  it  might  have  revealed  some  explanation  of  the  exceptional  nature 
of  this  moraine.  It  would  be  interesting  to  learn  whether  it  belongs 
to  the  greater  ice  age,  or  to  that  period  of  minor  glaciation  that 
fashioned  the  farm  patches  already  described.  The  formation  of  the 
lake  is  easily  understood  in  the  latter  case.  It  is  only  required  that 
such  a  minor  reglaciated  valley  as  one  of  these  should  be  of  larger 
magnitude  and  of  very  gentle  inclination  at  its  lower  part,  so  that 
the  secondary  glacier  should  die  out  before  reaching  the  present  sea- 
shore. It  would  then  deposit  its  moraine  across  the  mouth  of  the 
valley,  and  this  moraine  would  dam  up  the  waters  which  such  a  val- 
ley niust  necessarily  receive  from  the  drainage  of  its  hilly  sides. 
Llyn  Idwal,  in  North  Wales,  is  a  lake  thus  formed. 


THE    "GREAT   ICE   AGE."  161 

But  this  negative  anomaly  is  not  all.  The  ancient  glacial 
deposits  are  not  only  remarkable  on  account  of  the  absence  of 
the  most  characteristic  of  modern  glacial  deposits,  but  in  con- 
sisting mainly  of  something  which  is  quite  different  from  any 
of  the  deposits  actually  formed  by  any  of  the  modern  glaciers 
of  Switzerland  or  any  other  country  within  the  temperate 
zones. 

I  have  seen  nothing  either  at  the  foot  or  the  sides  of  any 
living  Alpine  or  Scandinavian  glacier  that  even  approximately 
represents  the  ll  till  "  or  "  boulder  clay,"  nor  any  description 
of  such  a  formation  by  any  other  observer  ;  and  have  met  with 
no  note  of  this  very  suggestive  anomaly  by  any  writer  on  gla- 
ciers. Yet  the  till  and  boulder  clay  form  vast  deposits,  cover- 
ing thousands  of  square  miles  even  of  the  limited  area  of  the 
British  Isles,  and  constitute  the  main  evidence  upon  which  we 
base  all  our  theories  respecting  the  existence  and  the  vast  ex- 
tent and  influence  of  the  "  Great  Ice  Age." 

Although  so  different  from  anything  at  present  produced  by 
the  Alpine  or  Scandinavian  glaciers,  this  great  deposit  is  un- 
questionably of  glacial  origin.  The  evidences  upon  which  this 
general  conclusion  rests  are  fully  stated  by  Mr.  Geikie,  and 
may  safely  be  accepted  as  incontrovertible.  Whence,  then, 
the  great  difference  ? 

One  of  the  suggestions  to  which  I  have  already  alluded  as 
afforded  by  reading  Mr.  Geikie's  book  was  a  hypothetical  solu- 
tion of  this  difficulty,  but  the  verification  of  the  hypothesis 
demanded  a  revisit  to  Norway.  An  opportunity  for  this  was 
afforded  in  the  summer  of  1874,  during  which  I  travelled  round 
the  coast  from  Stavanger  to  the  Arctic  frontier  of  Russia,  and 
through  an  interesting  inland  district.  The  observations  there 
made,  and  strengthened  by  subsequent  reflections,  have  so  far 
confirmed  my  original  speculative  hypothesis  that  I  now  ven- 
ture to  state  it  briefly  as  follows  : 

That  the  period  appropriately  designated  by  Mr.  Geikie  as  the 
"  Great  Ice  Age"  includes  at  least  two  distinct  periods  or 
epochs — the  first  of  very  great  intensity  or  magnitude,  during 
which  the  Arctic  regions  of  our  globe  were  as  completely  gla- 
ciated as  the  Antarctic  now  are,  and  the  British  islands  and  a 
large  portion  of  Northern  Europe  were  glaciated  as  completely, 
and  nearly  in  the  same  manner,  as  Greenland  is  at  the  present 
time  ;  that  long  after  this,  and  immediately  preceding  the 
present  geological  epoch,  there  was  a  minor  glacial  period, 
when  only  the  now  existing  valleys  favorably  shaped  and  situ- 


162  SCIENCE   IN    SHORT   CHAPl'ERS. 

ated  for  glacial  accumulations  were  partially  or  -wholly  filled 
with  ice.  There  may  have  been  many  intermediate  fluctua- 
tions of  climate  and  glaciation,  and  probably  were  such,  but  as 
these  do  not  affect  my  present  argument  they  need  not  be  here 
considered. 

So  far  I  agree  with  the  general  conclusions  of  Mr.  Geilde  as 
I  understand  them,  and  with  the  generally  received  hypothe- 
ses, but  in  what  follows  I  have  ventured  to  diverge  materially. 

It  appears  to  me  that  the  existing  Antarctic  glaciers  and 
some  of  the  glaciers  of  Greenland  are  essentially  different  in 
their  conformation  from  the  present  glaciers  of  the  Alps,  and 
from  those  now  occupying  some  of  the  fields  and  valleys  of 
Norway  ;  and  that  the  glaciers  of  the  earlier  or  greater  glacial 
epoch  were  similar  to  those  now  forming  the  Antarctic  barrier, 
while  the  glaciers  of  the  later  or  minor  glacial  epoch  resembled 
those  now  existing  in  temperate  climates,  or  were  intermediate 
between  these  and  the  Antarctic  glaciers.  The  nature  of  the 
difference  which  I  suppose  to  exist  between  the  two  classes  of 
glaciers  is  this  :  The  glaciers  (properly  so  called)  of  temperate 
climates  are  the  overflow  of  the  neve  (the  great  reservoir  of  ice 
and  snow  above  the  snow  line).  They  are  composed  of  ice 
which  is  protruded  below  the  snow-line  into  the  region  where 
the  summer  thaw  exceeds  the  winter  snowfall.  This  ice  is 
necessarily  subject  to  continual  thinning  or  wasting  from  its 
upper  or  exposed  surface,  and  thus  finally  becomes  liquefied, 
and  is  terminated  by  direct  solar  action. 

Many  of  the  characteristic  phenomena  of  Alpine  glaciers 
depend  upon  this  ;  among  the  more  prominent  of  which  are 
the  superficial  extrusion  of  boulders  or  rock  fragments  that 
have  been  buried  in  the  neve,  or  have  fallen  into  the  crevasses 
of  the  upper  part  of  the  true  glacier,  and  the  final  deposit  of 
these  same  boulders  or  fragments  at  the  foot  of  the  glaciers 
forming  ordinary  moraines. 

But  this  is  not  all.  The  thawing  which  extrudes,  and  finally 
deposits  the  larger  fragments  of  rock,  sifts  from  them  the 
smaller  particles,  the  aggregate  bulk  of  which  usually  exceeds 
very  largely  that  of  the  larger  fragments.  This  fine  silt  or  sand 
thus  washed  away  is  carried  by  the  turbid  glacier  torrent  to 
considerable  distances,  and  deposited  as  an  alluvium  wherever 
the  agitated  waters  find  a  resting-place. 

Thus  the  debris  of  the  ordinary  modern  glacier  is  effectively 
separated  into  two  or  more  very  distinct  deposits  ;  the  moraine 
at  the  glacier  foot  consisting  of  rock  fragments  of  considerable 


THE  "  GREAT  ICE  AGE/'  163 

size  with  very  little  sand  or  clay  or  other  fine  deposit  between 
them,  and  a  distant  deposit  of  totally  different  character,  con- 
sisting of  gravel,  sand,  clay,  or  mud,  according  to  the  length 
and  conditions  of  its  journey.  The  "  chips,"  as  they  have 
been  well  called,  are  thus  separated  from  what  I  may  designate 
the  filings  or  sawdust  of  the  glacier. 

The  filings  from  the  existing  glaciers  of  the  Bernese  Alps  are 
gradually  filling  up  the  lake-basins  of  Geneva  and  Constance, 
repairing  the  breaches  made  by  the  erosive  action  of  their 
gigantic  predecessors  ; '  those  of  the  southern  slope  of  the  Alps 
are  doing  a  large  share  in  filling  up  the  Adriatic  ;  while  the 
chips  of  all  merely  rest  upon  the  glacier  beds  forming  the  com- 
paratively insignificant  terminal  moraine  deposits. 

The  same  in  Scandinavia.  The  Storelv  of  the  Jostedal  is 
fed  by  the  melting  of  the  Krondal,  Nygaard,  Bjornestegs,  and 
Soldal  glaciers.  It  has  filled  up  a  branch  of  the  deep  Sogne 
fiord,  forming  an  extensive  fertile  plain  at  the  mouth  of  its 
wild  valley,  and  is  depositing  another  subaqueous  plain  beyond, 
while  the  moraines  of  the  glaciers  are  but  inconsiderable  and 
comparatively  insignificant  heaps  of  loose  boulders,  spread  out 
on  the  present  and  former  shores  of  the  above-named  glaciers, 
which  are  overflows  from  one  side  of  the  great  neve,  the  Joste- 
dal Sneefond.  All  of  these  glaciers  flow  down  small  lateral 
valleys,  spread  out,  and  disappear  in  the  main  valley,  which 
has  now  no  glacier  of  its  own,  though  it  was  formerly  glaciated 
throughout. 

What  must  have  been  the  condition  of  this  and  the  other 
great  Scandinavian  valleys  when  such  was  the  case  ?  To 
answer  this  question  rationally  we  must  consider  the  meteoro- 
logical conditions  of  that  period.  Either  the  climate  must 
hav^e  been  much  colder,  or  the  amount  of  precipitation  vastly 
greater  than  at  present,  in  order  to  produce  the  general  glacia- 
tion  that  rounded  the  mountains  up  to  a  height  of  some  thou- 
sands of  feet  above  the  present  sea-level.  Probably  both 
factors  co-operated  to  effect  this  vast  glaciation,  the  climate 
colder,  and  the  snowfall  also  greater.  The  whole  of  Scandi- 
navia, or  as  much  as  then  stood  above  the  sea,  must  have  been 
a  neve  or  sneefond  on  which  the  annual  snowfall  exceeded  the 
annual  thaw. 

This  is  the  case  at  present  on  the  largest  neve  of  Europe,  the 
500  square  miles  of  the  great  plateau  of  the  Jostedals  and 
Nordfjords  Sneefond  ;  on  all  the  overflowing  neve  or  snow- 
fields  of  the  Alps  above  the  snow-line  ;  over  the  greater  part  of 


lb'4  SCIENCE   IN   SHORT   CHAPTERS. 

Greenland  ;  and  (as  the  structure  of  the  southern  icebergs 
prove)  everywhere  within  the  great  Antarctic  ice  barrier. 

What,  then,  must  happen  when  the  snow-line  comes  down, 
or  nearly  down,  to  the  sea-level  ?  It  is  evident  that  the  out- 
thrust  glaciers,  the  overflow  down  the  valleys,  cannot  come  to 
an  end  like  the  present  Swiss  and  Scandinavian  glaciers,  by  the 
direct  melting  action  of  the  sun.  They  may  be  somewhat 
thinned  from  below  by  the  heat  of  the  earth,  and  that  gen- 
erated by  their  own  friction  on  the  rocks,  but  these  must  be 
quite  inadequate  to  overcome  the  perpetual  accumulation  due 
to  the  snowfall  upon  their  own  surface  and  the  vast  overflow 
from  the  great  snow-fields  above.  They  must  go  on  and  on, 
ever  increasing,  until  they  meet  some  new  condition  of  climate 
or  some  other  powerful  agent  of  dissipation — something  that 
can  effectively  melt  them. 

This  agent  is  very  near  at  hand  in  the  case  of  the  Scandina- 
vian valleys  and  those  of  Scotland.  It  is  the  sea.  I  think  I 
may  safely  say  that  the  valley  glaciers  of  these  countries  during 
the  great  ice  age  must  have  reached  the  sea,  and  there  have 
terminated  their  existence,  just  as  tho  Antarctic  glaciers  ter- 
minate at  the  present  Antarctic  ice- wall. 

What  must  happen  when  a  glacier  is  thus  thrust  out  to  sea  ? 
This  question  is  usually  answered  by  assuming  that  it  slides 
along  the  bottom  until  it  reaches  such  a  depth  that  flotation 
commences,  and  then  it  breaks  off  or  "  calves"  as  icebergs. 
This  view  is  strongly  expressed  by  Mr.  Geikie  (p.  47)  when  he 
says  that,  "The  seaward  portion  of  an  Arctic  glacier  cannot 
by  any  possibility  be  floated  up  without  sundering  its  connec- 
tion with  the  frozen  mass  behind.  So  long  as  the  bulk  of  the 
glacier  much  exceeds  the  depth  of  the  sea,  the  ice  will  of 
course  rest  upon  the  bed  of  the  fiord  or  bay  without  being  sub- 
jected to  any  strain  or  tension.  But  when  the  glacier  creeps 
outward  to  greater  depths,  then  the  superior  specific  gravity  of 
the  sea-water  will  tend  to  press  the  ice  upward.  That  ice, 
however,  is  a  hard  continuous  mass,  with  sufficient  cohesion  to 
oppose  for  a  time  this  pressure,  and  hence  the  glacier  crawls 
on  to  a  depth  far  beyond  the  point  at  which,  had  it  been  free, 
it  would  have  risen  to  the  surface  and  floated.  If  at  this  great 
depth  the  whole  mass  of  the  glacier  could  be  buoyed  up  with- 
out breaking  off,  it  would  certainly  go  to  prove  that  the  ice  of 
Arctic  regions,  unlike  ice  anywhere  else,  had  the  property  of 
yielding  to  mechanical  strain  without  rupturing.  But  the  great 
tension  to  which  it  is  subjected  takes  effect  in  the  usual  way, 
and  the  ice  yields,  not  by  bending  and  stretching,  but  by 


THE    "  GREAT   ICE   AGE."  165 

breaking."  Mr.  Geikic  illustrates  this  by  a  diagram  showing 
the  **  calving"  of  an  iceberg. 

In  spite  of  my  respect  for  Mr.  Geikie  as  a  geological 
authority,  I  have  no  hesitation  in  contradicting  some  of  the 
physical  assumptions  included  in  the  above. 

Ice  has  no  such  rigidity  as  here  stated.  It  does  possess  in  a 
high  degree  "  the  property  of  yielding  to  mechanical  strain 
without  rupturing."  We  need  not  go  far  for  evidence  of 
this.  Everybody  who  has  skated  or  seen  others  skating  on  ice 
that  is  but  just  thick  enough  to  "  bear"  must  have  felt  or  seen 
it  yield  to  the  mechanical  strain  of  the  skater's  weight. 
Under  these  conditions  it  not  only  bends  under  him,  but  it 
afterward  yields  to  the  reaction  of  the  water  below,  rising  and 
falling  in  visible  undulations,  demonstrating  most  unequivocally 
a  considerable  degree  of  flexibility.  It  may  be  said  that  in  this 
case  the  flexibility  is  due  to  the  thinness  of  the  ice  ;  but  this 
argument  is  unsound,  inasmuch  as  the  manifestation  of  such 
flexibility  does  not  depend  upon  absolute  thickness  or  thinness, 
but  upon  the  relation  of  thickness  to  superficial  extension.  If 
a  thin  sheet  of  ice  can  be  bent  to  a  given  arc,  a  thick  sheet 
may  be  bent  in  the  same  degree,  but  the  thicker  ice  demands  a 
greater  radius  and  proportionate  extension  of  circumference. 
But  we  have  direct  evidence  that  ice  of  great  thickness — actual 
glaciers — may  bend  to  a  considerable  curvature  before  breaking. 
This  is  seen  very  strikingly  when  the  uncrevassed  ice-sheet  of  a 
slightly  inclined  neve  suddenly  reaches  a  precipice  and  is  thrust 
over  it.  If  Mr.  Geikie  were  right,  the  projecting  cornice  thus 
formed  should  stand  straight  out,  and  then,  when  the  trans- 
verse strain  due  to  the  weight  of  this  rigid  overhang  exceeded 
the  resistance  of  tenacity,  it  should  break  off  short,  exposing  a 
face  at  right  angles  to  the  general  surface  of  the  supported 
body  of  ice.  Had  Mr.  Geikie  ever  seen  and  carefully  observed 
such  an  overhang  or  cornice  of  ice,  I  suspect  that  the  above 
quoted  passage  would  not  have  been  written. 

Some  very  fine  examples  of  such  ice-cornices  are  well  seen 
from  the  ridge  separating  the  Handspikjen  Fjelde  from  the 
head  of  the  Jostedal,  where  a  view  of  the  great  neve  or  snee- 
fond  is  obtained.  This  side  of  the  neve  terminates  in  precipi- 
tous rock-walls  ;  at  the  foot  of  one  of  these  is  a  dreary  lake, 
the  Styggevand.  The  overflow  of  the  neve  here  forms  great 
bending  sheets  that  reach  a  short  way  down,  and  then  break  off 
and  drop  as  small  icebergs  into  the  lake.* 

*  See  "Through  Norway  with  a  Knapsack,''  chapters  xi.  and  xii., 
for  further  descriptions  of  these. 


166        •  SCIENCE   IK   SHOUT   CHAPTERS. 

The  ordinary  course  of  glaciers  affords  abundant  illustrations 
of  the  plasticity  of  such  masses  of  ice.  They  spread  out  where 
the  valley  widens,  contract  where  the  valley  narrows,  and  follow 
all  the  convexities  or  concavities  of  the  axial  line  of  its  bed. 
If  the  bending  thus  enforced  exceeds  a  certain  degree  of 
abruptness  crevasses  are  formed,  but  a  considerable  bending 
occurs  before  the  rupture  is  effected,  and  crevasses  of  consid- 
erable magnitude  are  commonly  formed  without  severing  one 
part  of  a  glacier  from  another.  They  are  usually  V-shaped,  in 
vertical  section,  and  in  many  the  rupture  does  not  reach  the 
bottom  of  the  glacier.  Very  rarely  indeed  does  a  crevasse 
cross  the  whole  breadth  of  a  glacier  in  such  a  manner  as  to 
completely  separate,  even  temporarily,  the  lower  from  the 
upper  part  of  the  glacier. 

If  a  glacier  can  thus  bend  downward  without  * '  sundering 
its  connection  with  the  frozen  mass  behind,"  surely  it  may 
bend  upward  in  a  corresponding  degree,  either  with  or  without 
the  formation  of  crevasses,  according  to  the  thickness  of  the 
ice  and  the  degree  of  curvature. 

A  glacier  reaching  the  sea  by  a  very  steep  incline  would 
probably  break  off,  in  accordance  with  Mr.  Geikie's  descrip- 
tion, just  as  an  Alpine  glacier  is  ruptured  fairly  across  when  it 
makes  a  cascade  over  a  suddenly  precipitous  bend  of  its  path. 
One  entering  the  sea  at  an  inclination  somewhat  less  precipitous 
than  the  minor  limit  of  the  effective  rupture  gradient  would  be 
crevassed  in  a  contrary  manner  to  the  crevassing  of  Alpine 
glaciers.  Its  crevasses  would  gape  downward  instead  of  up- 
ward— have  a  A-shaped  instead  of  a  V-shaped  section. 

With  a  still  more  moderate  slope,  the  up- floating  of  the  ter- 
mination of  the  glacier,  and  a  concurrent  general  uplifting  or 
upbending  of  the  whole  of  its  submerged  portion  might  occur 
without  even  a  partial  rupture  or  crevasse  formation  occurring. 

Let  us  now  follow  out  some  of  the  necessary  results  of  these 
conditions  of  glacier  existence  and  glacial  prolongation.  The 
first  and  most  notable,  by  its  contrast  with  ordinary  glaciers,  is 
the  absence  of  lateral,  medial,  or  terminal  moraines.  The 
larger  masses  of  debris,  the  chippings  that  may  have  fallen 
from  the  exposed  escarpments  of  the  mountains  upon  the  sur- 
face of  the  upper  regions  of  the  glacier,  instead  of  remaining 
on  the  surface  of  the  ice  and  standing  above  its  general  level 
by  protecting  the  ice  on  which  they  rest  from  the  general 
snow-thaw,  would  become  buried  by  the  upward  accretion  of 
the  ice  due  to  the  unthawed  stratum  of  each  year's  snowfall. 


THE    "GREAT   ICE   AGE."  167 

The  thinning  agency  at  work  upon  such  glaciers  during  their 
journey  over  the  terra  firma  being  the  outflow  of  terrestrial 
heat  and  that  due  to  their  friction  upon  their  beds,  this  thin- 
ning must  all  take  place  from  below,  and  thus,  as  the  glacier 
proceeds  downward,  these  rock  fragments  must  be  continually 
approaching  the  bottom  instead  of  continually  approaching  the 
top,  as  in  the  case  of  modern  Alpine  glaciers  flowing  below  the 
snow-line,  and  thawing  from  surface  downward. 

It  follows,  therefore,  that  such  glaciers  could  not  deposit  any 
moraines  such  as  are  in  course  of  deposition  by  existing  Alpine 
and  Scandinavian  glaciers. 

What,  then,  must  become  of  the  chips  and  filings  of  these 
outfloating  glaciers  ?  They  must  be  carried  along  with  the 
ice  so  long  as  that  ice  rests  upon  the  land  ;  for  this  debris  must 
consist  partly  of  fragments  imbedded  in  the  ice,  and  partly  of 
ground  and  reground  excessively  subdivided  particles,  that 
must  either  cake  into  what  I  may  call  ice-mud,  and  become  a 
part  of  the  glacier,  or  flow  as  liquid  mud  or  turbid  water  be- 
neath it,  as  with  ordinary  glaciers.  The  quantity  of  water  be- 
ing relatively  small  under  the  supposed  conditions,  the  greater 
part  would  be  carried  forward  to  the  sea  by  the  ice  rather  than 
by  the  water. 

An  important  consequence  of  this  must  be  that  the  erosive 
power  of  these  ancient  glaciers  was,  cceteris  paribus,  greater 
than  that  of  modern  Alpine  glaciers,  especially  if  we  accept 
those  theories  which  ascribe  an  actual  internal  growth  or  regen- 
eration of  glaciers  by  the  relegation  below  of  some  of  the  water 
resulting  from  the  surface-thaw. 

As  the  glacier  with  its  lower  accumulation  advances  into 
deeper  and  deeper  water,  its  pressure  upon  its  bed  must  pro- 
gressively diminish  until  it  reaches  a  line  where  it  would  just 
graze  the  bottom  with  a  touch  of  feathery  lightness.  Some- 
where before  reaching  this  it  would  begin  to  deposit  its  burden 
on  the  sea-bottom,  the  commencement  of  this  deposition  being 
determined  by  the  depth  whereat  the  tenacity  of  the  deposit, 
or  its  friction  against  the  sea-bottom,  or  both  combined,  be- 
.  comes  sufficient  to  overpower  the  now-diminished  pressure  and 
forward  thrusting,  or  erosive  power  of  the  glacier. 

Further  forward,  in  deeper  water,  where  the  ice  becomes 
fairly  floated  above  the  original  sea-bottom,  a  rapid  under- 
thawing  must  occur  by  the  action  of  the  sea-water,  and  if  any 
communication  exists  between  this  ice-covered  sea  and  the 
waters  of  wanner  latitudes,  this  thawing  must  be  increased  by 


168  SCIENCE   IN   SHORT   CHAPTERS. 

the  currents  that  would  necessarily  be  formed  by  the  inter- 
change of  water  of  varying  specific  gravities.  Deposition 
would  thus  take  place  in  this  deeper  water,  continually  shallow- 
ing it  or  bringing  up  the  sea-bottom  nearer  to  the  ice-bottom. 

This  raising  of  the  sea-bottom  must  occur  not  only  here,  but 
farther  back — i.e.  from  the  limit  at  which  deposition  com- 
menced. This  neutral  ground,  whereat  the  depth  is  just  suffi- 
cient to  allow  the  ice  to  rest  lightly  on  its  own  deposit  and 
slide  over  it  without  either  sweeping  it  forward  or  depositing 
any  more  upon  it,  becomes  an  interesting  critical  region,  sub- 
ject to  continuous  forward  extension  during  the  lifetime  of  the 
glacier,  as  the  deposition  beyond  it  must  continually  raise  the 
sea-bottom  until  it  reaches  the  critical  depth  at  which  the  de- 
position must  cease.  This  would  constitute  what  I  may  desig- 
nate the  normal  depth  of  the  glaciated  sea,  or  the  depth  toward 
which  it  would  be  continually  tending,  during  a  great  glacial 
epoch,  by  the  formation  of  a  submarine  bank  or  plain  of 
glacial  deposit,  over  which  the  glacier  would  slide  without 
either  grinding  it  lower  by  erosion  or  raising  it  higher  by 
deposition. 

But  what  must  be  the  nature  of  this  deposit  ?  It  is  evident 
that  it  cannot  be  a  mere  moraine  consisting  only  of  the  larger 
fragments  of  rock  such  as  are  now  deposited  at  the  foot  of 
glaciers  that  die  out  before  reaching  the  sea.  Neither  can  it 
correspond  to  the  glacial  silt  which  is  washed  away  and  sepa- 
rated from  these  larger  fragments  by  glacial  streams,  and  de- 
posited at  the  outspreadings  of  glacial  torrents  and  rivers.  It 
will  correspond  to  neither  the  assorted  gravel,  sand,  nor  mud 
of  these  alluvial  deposits,  but  must  be  an  agglomeration  of  all 
the  infusible  solid  matter  the  glacier  is  capable  of  carrying. 

It  must  contain,  in  heterogeneous  admixture,  the  great 
boulders,  the  lesser  rock  fragments,  the  gravel  chips,  the  sand, 
and  the  slimy  mud  ;  these  settling  down  quietly  in  the  cold, 
gloomy  waters,  overshadowed  by  the  great  ice-sheet,  must  form 
just  such  an  agglomeration  as  we  find  in  the  boulder  clay  and 
tills,  and  lie  just  in  those  places  where  these  deposits  abound, 
provided  the  relative  level  of  land  and  sea  during  the  glacial 
epoch  were  suitable. 

I  should  make  one  additional  remark  relative  to  the  composi- 
tion of  this  deposit — viz.  that  under  the  conditions  supposed, 
the  original  material  detached  from  the  rocks  around  the  upper 
portions  of  the  glaciers  would  suffer  a  far  greater  degree  of 
attrition  at  the  glacier  bottom  than  it  obtains  in  modern  Alpine 


THE    "  GREAT   ICE   AGE."  169 

glaciers,  inasmuch  as  in  these  it  is  removed  by  the  glacier  tor- 
rent when  it  has  attained  a  certain  degree  of  fineness,  while  in 
the  greater  glaciers  of  the  glacial  epoch  it  would  be  carried 
much  further  in  association  with  the  solid  ice,  and  be  subjected 
to  more  grinding  and  regrinding  against  the  bottom.  Hence  a 
larger  proportion  of  slimy  mud  would  be  formed,  capable  of 
finally  indurating  into  stiff  clay  such  as  forms  the  matrix  of  the 
till  and  boulder  clay. 

The  long  journey  of  the  bottom  debris  stratum  of  the  glacier, 
and  its  final  deposition  when  in  a  state  of  neutral  equilibrium 
between  its  own  tendency  to  repose  and  the  forward  thrust  of 
the  glacier,  would  obviously  tend  to  arrange  the  larger  frag- 
ments of  rock  in  the  manner  in  which  they  are  found  imbed- 
ded in  the  till — i.e.  the  oblong  fragments  lying  with  their  longer 
axes  and  their  best  marked  striae  in  the  direction  of  the  motion 
of  the  glacier.  The  "  striated  pavements"  of  the  till  are  thus 
easily  explained  ;  they  are  the  surface  upon  which  the  ice  ad- 
vanced when  its  deposits  had  reached  the  critical  or  neutral 
height.  Such  a  pavement  would  continually  extend  outward. 

The  only  sorting  of  the  material  likely  to  occur  under  these 
conditions  would  be  that  due  to  the  earlier  deposition  and 
entanglement  of  the  larger  fragments,  thus  producing  a  more 
stony  deposit  nearer  inland,  just  as  Mr.  Geikie  describes  the 
actual  deposits  of  till  where,  "  generally  speaking,  the  stones 
are  most  numerous  in  the  till  of  hilly  districts  ;  while  at  the 
lower  levels  of  the  country  the  clayey  character  of  the  mass  is 
upon  the  whole  more  pronounced."  These  "  hilly  districts," 
upon  the  supposition  of  greater  submergence,  would  be  the 
near  shore  regions,  and  the  lower  levels  the  deeper  sea  where 
the  glacier  floated  freely. 

The  following  is  Mr.  Geikie's  description  of  the  distribution 
of  the  till  (page  13)  :  "It  is  in  the  lower-lying  districts  of  the 
country  where  till  appears  in  greatest  force.  Wide  areas  of  the 
central  counties  are  covered  up  with  it  continuously,  to  a  depth 
varying  from  two  or  three  feet  up  to  one  hundred  feet  and 
more.  But  as  we  follow  it  toward  the  mountain  regions  it  be- 
comes thinner  and  more  interrupted — the  naked  rock  ever  and 
anon  peering  through,  until  at  last  we  find  only  a  few  shreds 
and  patches  lying  here  and  there  in  sheltered  hollows  of  the 
hills.  Throughout  the  Northern  Highlands  it  occurs  but 
rarely,  and  only  in  little  isolated  patches.  It  is  not  until  we 
get  away  from  the  steep  rocky  declivities  and  narrow  glens  and 
gorges,  and  enter  upon  the  broader  valleys  that  open  out  from 


170  SCIENCE   IK   SHOUT   CHAPTERS. 

the  base  of  the  highland  mountains  to  the  low-lying  districts 
beyond,  that  we  meet  with  any  considerable  deposits  of  stony 
clay.  The  higher  districts  of  the  Southern  Uplands  are  almost 
equally  free  from  any  covering  of  till." 

This  description  is  precisely  the  same  as  I  must  have  written, 
had  I  so  far  continued  my  imaginary  sketch  of  the  results  of 
ancient  glaciation  as  to  picture  what  must  remain  after  the 
glaciers  had  all  melted  away,  and  the  sea  had  receded  suffi- 
ciently to  expose  their  submarine  deposits. 

Throughout  the  above  I  have  assumed  a  considerable  sub- 
mergence of  the  land  as  compared  with  the  present  sea-level  on 
the  coasts  of  Scotland,  Scandinavia,  etc. 

The  universality  of  the  terraces  in  all  the  Norwegian  valleys 
opening  westward  proves  a  submergence  of  at  least  600  or  700 
feet.  When  I  first  visited  Norway,  in  1856,  I  accepted  the  usual 
description  of  these  as  alluvial  deposits  ;  was  looking  for  glacial 
vestiges  in  the  form  of  moraines,  and  thus  quite  failed  to  ob- 
serve the  true  nature  of  these  vast  accumulations,  which  was 
obvious  enough  when  I  re-examined  them  in  the  light  of  more 
recent  information.  Some  few  are  alluvial,  but  they  are  ex- 
ceptional and  of  minor  magnitude.  As  an  example  of  such 
alluvial  terraces  I  may  mention  those  near  the  mouth  of  the 
Komsdal,  that  arc  well  seen  from  the  Aak  Hotel,  and  which  a 
Russian  prince,  or  other  soldier  merely  endowed  with  military 
eyes,  might  easily  mistake  for  artificial  earthworks  erected  for 
the  defence  of  the  valley. 

In  this  case,  as  in  the  others  where  the  terraces  are  alluvial, 
the  valley  is  a  narrow  one,  occupied  by  a  relatively  wide  river 
loaded  with  recent  glacial  debris.  It  evidently  filled  the  valley 
during  the  period  of  glacial  recession. 

The  ordinary  wider  valleys,  with  a  river  that  has  cut  a  nar- 
row channel  through  the  outspread  terrace-flats,  display  a 
different  formation.  Near  the  mouth  of  such  valleys  I  have 
seen  cuttings  of  more  than  a  hundred  feet  in  depth,  through  an 
unbroken  terrace  of  most  characteristic  till,  with  other  traces 
rising  above  it.  This  is  the  ordinary  constitution  of  the  lower 
portions  of  most  of  the  Scandinavian  terraces. 

These  terraces  are  commonly  topped  with  quite  a  different 
stratum,  which  at  first  I  regarded  as  a  subsequent  alluvial  or 
estuarine  deposit,  but  further  examination  suggested  another 
explanation  of  the  origin  of  some  portions  of  this  superficial 
stratum,  to  which  I  shall  refer  hereafter. 

Such  terraces  prove  a  rise  of  sea  or  depression  of  land,  dur- 


THE    "  GKEAT   ICE   AGE."  171 

ing  the  glacial  epoch,  to  the  extent  of  600  feet  as  a  minimum, 
while  the  well-known  deposits  of  Arctic  shells  at  Moel  Tryfaen 
and  the  accompanying  drift  have  led  Professor  Ramsay  to  esti- 
mate "  the  probable  amount  of  submergence  during  some  part 
of  the  glacial  period  atabout  2300  feet."  * 

It  would  be  out  of  place  here  to  reproduce  the  data  upon 
which  geologists  have  based  their  rather  divergent  opinions 
respecting  the  actual  extent  of  the  submergence  of  the  western 
coast  of  North  Europe.  All  agree  that  a  great  submergence 
occurred,  but  differ  only  as  to  its  extent,  their  estimates  vary- 
ing between  1000  and  3000  feet. 

There  is  one  important  consideration  that  must  not  be  over- 
looked— viz.  that  if  my  view  of  the  submarine  origin  of  the 
till  be  correct,  the  mere  submergence  of  the  land  at  the  glacial 
period  does  not  measure  the  difference  between  the  depth  of 
the  sea  at  that  and  the  present  time,  seeing  that  the  deposits 
from  the  glaciers  must  have  shallowed  it  very  materially. 

It  is  only  after  contemplating  thoughtfully  the  present  form 
of  the  granitic  and  metamorphic  hills  of  Scandinavia — hills  that 
are  always  angular  when  subjected  only  to  sub-aerial  weather- 
ing— that  one  can  form  an  adequate  conception  of  the  magni- 
tude of  this  shallowing  deposit.  The  rounding,  shaving, 
grinding,  planing,  and  universal  abrasion  everywhere  displayed 
appear  to  me  to  justify  the  conclusion  that  if  the  sea  were  now 
raised  to  the  level  of  the  terraces — i.e.  600  feet  higher  than  at 
present — the  mass  of  matter  abraded  from  the  original  Scandi- 
navian mountains,  and  lying  under  the  sea,  would  exceed  the 
whole  mass  of  mountain  left  standing  above  it. 

The  first  question  suggested  by  reading  Mr.  Geikie's  book 
was  whether  the  terraces  are  wholly  or  partially  formed  of  till, 
and  more  especially  whether  their  lower  portions  are  thus  com- 
posed. This,  as  already  stated,  was  easily  answered  by  the 
almost  unanimous  reply  of  all  the  many  Norwegian  valleys  I 
traversed.  Any  tourist  may  verify  this.  The  next  question 
was  whether  this  same  till  extends  below  the  sea.  This  was 
not  so  easily  answered  by  the  means  at  my  disposal,  as  I 
travelled  hastily  round  the  coast  from  Stavanger  via  the  North 
Cape  to  the  frontier  of  Russian  Lapland  in  ordinary  passenger 
steam-packets,  which  made  their  stoppages  to  suit  other  re- 
quirements than  mine.  Still  I  was  able  to  land  at  many  sta- 
tions, and  found,  wherever  there  was  a  gently  sloping  strand 

*  Lyell,  "  Elements  of  Geology,"  p.  150. 


172  SCTEXCE   IX    bilOJiT   CHAFTEKS. 

at  the  mouth  of  an  estuary,  or  of  a  valley  whose  river  had 
already  deposited  its  suspended  matter  (a  common  case  here- 
abouts, where  so  many  rivers  terminate  in  long  estuaries  or 
open  out  into  bag-shaped  lakes  near  the  coast),  and  where  the 
bottom  had  not  been  modified  by  secondary  glaciation,  that  the 
receding  tide  displayed  a  sea-bottom  of  till,  covered  with  a  thin 
stratum  of  loose  stones  and  shells.  In  some  cases  the  till  was 
so  bare  that  it  appeared  like  a  stiff  mud  deposited  but  yesterday. 

At  Bodo,  an  Arctic  coast  station  on  the  north  side  of  the 
mouth  of  the  Salten  fiord  (lat.  67°  20'),  where  the  packets 
make  a  long  halt,  is  a  very  characteristic  example  of  this  :  a 
deposit  of  very  tough  till  forming  an  extensive  plain  just  on 
the  sea-level.  The  tide  rises  over  this,  and  the  waves  break 
upon  it,  forming  a  sort  of  beach  by  washing  away  some  of  the 
finer  material,  and  leaving  the  stones  behind.  The  ground  be- 
ing so  nearly  level,  the  reach  of  the  tide  is  very  great,  and  thus 
a  large  area  is  exposed  at  low  tide.  Continuous  with  this,  and 
beyond  the  limit  of  high  tide,  is  an  extensive  inland  plain  cov- 
ered with  coarse  grass  and  weeds  growing  directly  upon  the 
surface  of  the  original  flat  pavement  of  till. 

There  is  no  river  at  Bodo  ;  the  sea  is  clear,  leaves  no  appre- 
ciable deposit,  and  the  degree  of  denudation  of  the  clayey 
matrix  of  the  till  is  very  much  smaller  than  might  be  expected. 
The  limit  of  high  water  is  plainly  shown  by  a  beach  of  shells 
and  stones,  but  at  low  tide  the  ground  over  which  the  sea  has 
receded  is  a  bare  and  scarcely  modified  surface  of  till.  I  have 
observed  the  same  at  low  water  at  many  other  Arctic  stations. 
In  the  Tromso  Sund  there  are  shallows  at  some  distance  from 
the  shore  which  are  just  covered  with  water  at  low  tide.  I 
landed  and  wade4  on  these,  and  found  the  bottom  to  consist  of 
till  covered  with  a  thin  layer  of  shells,  odd  fragments  of 
earthenware,  and  other  rubbish  thrown  overboard  from  vessels. 
It  is  evident  that  breakers  of  considerable  magnitude  are  neces- 
sary for  the  loosening  of  this  tough  compact  deposit— that  it  is 
very  slightly,  if  at  all,  affected  by  the  mere  flow  of  running 
water. 

I  specify  these  instances  as  characteristic  and  easy  of  verifi- 
cation, as  the  packets  all  stop  at  these  stations  ;  but  a  yachts- 
man sailing  at  leisure  amid  the  glorious  coast  scenery  of  the 
Arctic  Ocean  might  multiply  such  observations  a  hundredfold 
by  stopping  wherever  such  strands  are  indicated  in  passing.  I 
saw  a  multitude  of  these  in  places  where  I  was  unable  to  go 
ashore  and  examine  them. 


THE    "GREAT   ICE   AGE.''  173 

A  further  question  in  this  direction  suggested  itself  on  the 
gpot — viz.  what  is  the  nature  of  the  "  banks'1  which  constitute 
the  fishing-grounds  of  Norway,  Iceland,  Newfoundland,  etc. 
They  are  submarine  plains  unquestionably — they  must  have  a 
high  degree  of  fertility  in  order  to  supply  food  for  the  hun- 
dreds of  millions  of  voracious  codfish,  coal- fish,  haddocks, 
halibut,  etc.  that  people  them.  These  large  fishes  all  feed  on 
the  bottom,  their  chief  food  being  mollusca  and  Crustacea,  which 
must  find,  either  directly  or  indirectly,  some  pasture  of  vegeta- 
ble origin.  The  banks  are,  in  fact,  great  meadows  or  feeding 
grounds  for  the  lower  animals  which  support  the  higher. 

From  the  Lofoten  bank  alone  twenty  millions  of  codfish  are 
taken  annually,  besides  those  devoured  by  the  vast  multitude 
of  sea-birds.  Now  this  bank  is  situated  precisely  where,  ac- 
cording to  the  above-stated  view  of  the  origin  of  the  till,  there 
should  be  a  huge  deposit.  It  occupies  the  Vest  fiord — i.e.  the 
opening  between  the  mainland  and  the  Lofoden  Islands,  ex- 
tending from  Moskenes,  to  Lodingen  on  Ilindo,  just  where  the 
culminating  masses  of  the  Kjolen  Mountains  must  have  poured 
their  greatest  glaciers  into  the  sea  by  a  westward  course,  and 
these  glaciers  must  have  been  met  by  another  stream  pouring 
from  the  north,  formed  by  the  glaciers  of  Hindo  and  Senjeno, 
and  both  must  have  coalesced  with  a  third  flood  pouring 
through  the  Ofoten  fiord,  the  Tys  fiord,  etc.,  from  the  main- 
land. The  Vest  fiord  is  about  sixty  miles  wide  at  its  mouth, 
and  narrows  northward  till  it  terminates  in  the  Ofoten  fiord, 
which  forks  into  several  branches  eastward.  A  glance  at  a 
good  map  will  show  that  here,  according  to  my  explanation  of 
the  origin  of  the  till,  there  should  be  the  greatest  of  all  the 
submarine  plains  of  till  which  the  ancient  Scandinavian  glaciers 
have  produced,  and  of  which  the  plains  of  till  I  saw  on  the 
coast  at  Bodo  (which  lies  just  at  the  mouth  of  the  Vest  fiord, 
where  the  Salten  fiord  flows  into  it),  are  but  the  slightly  in- 
clined continuation. 

Some  idea  of  this  bank  may  be  formed  from  the  fact  that 
outside  of  the  Lofodcns  the  sea  is  100  to  200  fathoms  in  depth, 
that  it  suddenly  shoals  up  to  16  or  20  fathoms  on  the  east  side 
of  these  rocks,  and  this  shallow  plain  extends  across  the  whole 
50  or  60  miles  between  these  islands  and  the  mainland.*  It 

*  The  celebrated  "  Maelstrom"  is  one  of  the  currents  that  flow- 
down  the  submarine  incline  between  these  islands  when  the  tide  is 
falling.  Although  I  have  ridiculed  some  of  the  accounts  of  this  now 
innocent  stream,  I  am  not  prepared  to  assert  that  it  was  always  as  mild 


174  SCIENCE   12^   SHORT   CHAPTERS. 

must  not  be  supposed  the  fiords  or  inlets  of  Scandinavia  are 
usually  shallower  than  the  open  sea  ;  the  contrary  is  commonly 
the  case,  especially  with  the  narrowest  and  those  which  run 
farthest  inland.  They  are  very  much  deeper  than  the  open  sea. 

If  space  permitted  I  could  show  that  the  great  Storregen 
bank,  opposite  Aalesund  and  Molde,  where  the  Stor  fiord, 
Mold  fiord,  etc.  were  the  former  outlets  of  the  glaciers  from 
the  highest  of  all  the  Scandinavian  mountains,  and  the  several 
banks  of  Finmark,  etc.,  from  which,  in  the  aggregate,  are 
taken  another  20  or  30  millions  of  codfish  annually,  are  all 
situated  just  where  theoretically  they  ought  to  be  found.  The 
same  is  the  case  with  the  great  bank  of  Newfoundland  and  the 
banks  around  Iceland,  which  are  annually  visited  by  large 
numbers  of  French  fishermen  from  Dunkerque,  Boulogne,  and 
other  ports. 

Whenever  the  packet  halted  over  these  banks  during  our 
coasting  trip  we  demonstrated  their  fertility  by  casting  a  line 
or  two  over  the  bulwark.  No  bait  was  required,  merely  a 
double  hook  with  a  fiat  shank  attached  to  a  heavy  leaden 
plummet.  The  line  was  sunk  till  the  lead  touched  the  bottom, 
a  few  jerks  were  given,  and  then  a  tug  was  felt  :  the  line  was 
hauled  in  with  a  codfish  or  halibut  hooked,  not  inside  the 
mouth,  but  externally  by  the  gill-plates,  the  back,  the  tail  or 
otherwise.  The  mere  jerking  of  a  hook  near  the  bottom  was 
sufficient  to  bring  it  in  contact  with  some  of  the  population. 
There  is  a  very  prolific  bank  lying  between  the  North  Cape  and 
Nordkyn,  where  the  Porsanger  and  Laxe  fioids  unite  their 
openings.  Here  we  were  able,  with  only  three  lines,  to  cover 
the  fore-deck  of  the  packet  with  struggling  victims  in  the 
course  of  short  halts  of  fifteen  to  thirty  minutes.  Not  having 
any  sounding  apparatus  by  which  to  fairly  test  the  nature  of 
the  sea-bottom  in  these  places,  1  cannot  offer  any  direct  proof 
that  it  was  composed  of  till.  By  dropping  the  lead  I  could 
feel  it  sufficiently  to  be  certain  that  it  was  not  rock  in  any  case, 
but  a  soft  deposit,  and  the  marks  upon  the  bottom  of  the  lead, 

as  at  present.  If  the  ancient  glaciers  were  stopped  suddenly,  as 
they  may  well  have  been,  by  the  rocky  barrier  of  Mosken,  between 
Vaerft  and  Moskeneso,  and  they  then  suddenly  concluded  their 
deposition  of  till,  a  precipice  must  have  been  formed  between  this 
and  the  deep  sea  outside  the  islands,  down  which  the  sea  would 
pitch  when  the  tide  was  falling,  and  thus  form  some  dangerous 
eddies.  This  cascade  would  gradually  obliterate  itself  by  wearing 
down  the  precipitous  wall  to  an  inclined  plane  such  as  at  present  ex- 
ists, and  down  which  the  existing  current  flows. 


THE    "GREAT   ICE   AGE."  175 

so  far  as  they  went,  afforded  evidence  in  favor  of  is  clayey 
character.  A  further  investigation  of  this  would  be  very  in- 
teresting. 

But  the  most  striking — I  may  say  astounding — evidence  of 
the  fertility  of  these  banks,  one  which  appeals  most  powerfully 
to  the  senses,  is  the  marvellous  colony  of  sea-birds  at  Sverholt- 
klubben,  the  headland  between  the  two  last-named  fiords.  I 
dare  not  estimate  the  numbers  that  rose  from  the  rocks  and 
darkened  the  sky  when  we  blowed  the  steam-whistle  in  passing. 
I  doubt  whether  there  is  any  other  spot  in  the  world  where  an 
equal  amount  of  animal  life  is  permanently  concentrated.  All 
these  feed  on  fish,  and  an  examination  of  the  map  will  show 
why — in  accordance  with  the  above  speculations — they  should 
have  chosen  Sverholtklubben  as  the  best  fishing-ground  on  the 
Arctic  face  of  Europe. 

I  am  fully  conscious  of  the  main  difficulty  that  stands  in  the 
way  of  my  explanation  of  the  formation  of  the  till — viz.  that 
of  finding  sufficient  water  to  float  the  ice,  and  should  have 
given  it  up  had  I  accepted  Mr.  Geikie's  estimate  of  the  thick- 
ness of  the  great  ice-sheet  of  the  great  ice  age. 

He  says  (page  186)  that  "  The  ice  which  covered  the  low 
grounds  of  Scotland  during  the  early  cold  stages  of  the  glacial 
epoch  was  certainly  more  than  2000  feet  in  thickness,  and  it 
must  have  been  even  deeper  than  this  between  the  mainland 
and  the  Outer  Hebrides.  To  cause  such  a  mass  to  float,  the 
sea  around  Scotland  would  require  to  become  deeper  than  now 
by  1400  or  1500  feet  at  least." 

I  am  unable  to  understand  by  what  means  Mr.  Geikic 
measured  this  depth  of  the  ice  which  covered  these  low 
grounds,  except  by  assuming  that  its  surface  was  level  with 
that  of  the  upper  ice-marks  of  the  hills  beyond.  The  follow- 
ing passage  on  page  03  seems  to  indicate  that  he  really  has 
measured  it  thus  : 

"  Now  the  scratches  may  be  traced  from  the  islands  and  the 
coast-line  up  to  an  elevation  of  at  least  3500  feet  ;  so  that  ice 
must  have  covered  the  country  to  that  height  at  least.  In  the 
Highlands  the  tide  of  ice  streamed  out  from  the  central  eleva- 
tions down  all  the  main  straths  and  glens  ;  and  by  measuring 
the  height  attained  by  the  smoothed  and  rounded  rocks  we 
are  enabled  to  estimate  roughly  the  probable  thickness  of  the 
old  ice-sheet.  But  it  can  only  be  a  rough  estimate,  for  so 
long  a  time  has  elapsed  since  the  ice  disappeared,  the  rain  and 
frost  together  have  so  split  up  and  worn  down  the  rocks  of 


176  SCIENCE   IX   SHORT   CHAPTERS. 


these  highland  mountains  that  much  of  the  smoothing  and 
polishing  has  vanished.  But  although  the  finer  marks  of  the 
ice-chisel  have  thus  frequently  been  obliterated,  yet  the 
broader  effects  remain  conspicuous  enough.  From  an  exten- 
sive examination  of  these  we  gather  that  the  ice  could  not  have 
been  less,  and  was  probably  more  than  3000  feet  thick  in  its 
deepest  parts. ' ' 

Page  80  he  says  :  "  Bearing  in  mind  the  vast  thickness 
reached  by  the  Scotch  ice-sheet,  it  becomes  very  evident  that 
the  ice  would  flow  along  the  bottom  of  the  sea  with  as  much 
ease  as  it  poured  across  the  land,  and  every  island  would  be 
surmounted  and  crushed,  and  scored  and  polished  just  as 
readily  as  the  hills  of  the  mainland  were." 

Mr.  Geikie  describes  the  Scandinavian  ice-sheet  in  similar 
terms,  but  ascribes  to  it  a  still  greater  thickness.  He  says 
(page  404)  :  "  The  whole  country  has  been  moulded  and 
rubbed  and  polished  by  an  immense  sheet  of  ice,  which  could 


OUTLYING  LOFODENS,  NOT  GLACIATED. 

hardly  have  been  less  than  6000  or  even  7000  feet  thick," 
and  he  maintains  that  this  spread  over  the  sea  and  coalesced 
with  the  ice-sheet  of  Scotland. 

My  recollection  of  the  Lofoden  Islands,  which  from  their  posi- 
tion afford  an  excellent  crucial  test  of  this  question,  led  me  to 
believe  that  their  configuration  presented  a  direct  refutation  of 
Mr.  Geikie's  remaikable  inference  ;  but  a  mere  recollection  of 
scenery  being  too  vague,  a  second  visit  was  especially  desira- 
ble in  reference  to  this  point.  The  result  of  the  special 
observations  I  made  during  this  second  visit  fully  confirmed 
the  impression  derived  from  memory. 

I  found  in  the  first  place  that  all  along  the  coast  from 
Stavanger  to  the  Varan ger  fiord  every  lock  near  the  shore  is 
glaciated  ;  among  the  thousands  of  low-lying  ridges  that  peer 
above  the  water  to  various  heights  none  near  the  mainland  are 
angular.  The  general  character  of  these  is  shown  in  the 
sketch  of  "  My  Sea  Serpent,"  in  the  last  edition  of  "  Through 
Norway  with  a  Knapsack.'' 


THE 


The  rocks  which  constitute  the  extreme  outlying  limits  of 
the  Lofoden  group,  and  which  are  between  60  and  70  miles 
from  the  shore,  although  mineralogically  corresponding  with 
those  near  the  shore,  are  totally  different  in  their  conformation, 
as  the  sketch  of  three  characteristic  specimens  plainly  shows. 
Mr.  Everest  very  aptly  compares  them  to  shark's  teeth. 
Proceeding  northward,  these  rocks  gradually  progress  in  mag- 
nitude, until  they  become  mountains  of  3000  to  4000  feet  in 
height  ;  their  outspread  bases  form  large  islands,  and  the  Vest- 
fiord  gradually  narrows. 

The  remarkably  angular  and  jagged  character  of  these  rocks 
when  weathered  in  the  air  renders  it  very  easy  to  trace  the 
limits  of  glaciation  on  viewing  them  at  a  distance.  The  outer- 
most and  smallest  rocks  show  from  a  distance  no  signs  of 
glaciation.  If  submerged,  the  ice  of  the  great  ice  age  was 
then  enough  to  float  over  without  touching  them  ;  if  they 
stood  above  the  sea,  as  at  present,  they  suffered  no  more 
glaciation  than  would  be  produced  by  such  an  ice-sheet  as  that 
of  the  "  paleocrystic  "  ice  recently  found  by  Captain  Nares 
on  the  north  of  Greenland.  Progressing  northward,  the 
glaciation  begins  to  become  visible,  running  up  to  about  100 
feet  above  the  sea-level  on  the  islands  lying  westward  and 
southward  of  Ost  Yaagen.  Further  northward  along  the 
coast  of  Ost  Vaagen  and  Hindo,  the  level  gradually  rises  to 
about  500  feet  on  the  northern  portion  of  Ost  Vaagen,  and  up 
to  more  than  1000  feet  on  Hindu,  while  on  the  mainland  it 
reaches  3000  to  4000  feet. 

A  remarkable  case  of  such  variation,  or  descent  of  ice-level, 
as  the  ice-sheet  proceeded  seaward,  is  shown  at  Tromso.  This 
small  oblong  island  (lat.  69°  40'),  on  which  is  the  capital 
town  of  Finmark,  lies  between  the  mainland  and  the  large 
mountainous  island  of  Kvalo,  with  a  long  sea-channel  on  each 
side,  the  Tromosund  and  the  Sandesund  ;  the  total  width  of 
these  two  channels  and  the  island  itself  being  about  four  or 
live  miles.  The  general  line  of  glaciation  from  the  mainland 
crosses  the  broadside  of  these  channels  and  the  island,  which 
has  evidently  been  buried  and  ground  down  to  its  present 
moderate  height  of  two  or  three  hundred  feet.  Both  the 
channels  are  till-paved.  On  the  east  or  inland  side  the 
mountains  near  the  coast  are  glaciated  to  their  summits — are 
simply  roches  moutonnees,  over  which  the  reindeer  of  the 
Tromsdal  Lapps  range  and  feed.  On  the  west  the  mountains 
are  dark,  pyramidal,  rfon-glaciated  peaks,  with  long  vertical 
snow-streaks  marking  their  angular  masses. 


178  SCIENCE    IX   SHOUT   CHAPTERS. 

The  contrast  is  very  striking  when  seen  from  the  highest 
part  of  the  island,  and  is  clearly  due  to  a  decline  in  the  thick- 
ness of  the  ice-sheet  in  the  coarse  of  its  journey  across  this 
narrow  channel.  Speaking  roughly  from  my  estimation,  I 
should  say  that  this  thinning  or  lowering  of  the  limits  of 
glaciation  exceeds  500  feet  between  the  opposite  sides  of  the 
channel,  which,  allowing  for  the  hill  slopes,  is  a  distance  of 
about  6  miles.  This  very  small  inclination  would  bring  a 
glacier  of  3000  feet  in  thickness  on  the  shore  down  to  the  sea- 
level  in  an  outward  course  of  30  miles,  or  about  half  the  dis- 
tance between  the  mainland  and  the  outer  rocks  of  the 
Lofodens  shown  in  the  engraving. 

I  am  quite  at  a  loss  to  understand  the  reasoning  upon  which 
Mr.  Geikie  bases  his  firm  conviction  respecting  the  depth  of 
the  ice-sheet  on  the  low  grounds  of  Scotland  and  Scandinavia. 
He  seems  to  assume  that  the  glaciers  of  the  great  ice  age  had 
little  or  no  superficial  down  slope  corresponding  to  the  inclina- 
tion of  the  base  on  which  they  rested.  I  have  considerable 
hesitation  in  attributing  this  assumption  to  Mr.  Geikie,  and 
would  rather  suppose  that  I  have  misunderstood  him,  as  it  is  a 
conclusion  so  completely  refuted  by  all  we  know  of  glacier 
phenomena  and  the  physical  laws  concerned  in  their  produc- 
tion ;  but  the  passages  I  have  quoted,  and  several  others,  are 
explicit  and  decided. 

Those  geologists  who  contend  for  the  former  existence  of  a 
great  polar  ice-cap  radiating  outwards  and  spreading  into  the 
temperate  zones  might  adopt  this  mode  of  measuring  its  thick- 
ness, but  Mr.  Geikie  rejects  this  hypothesis,  and  shows  by  his 
map  of  "  The  Principal  Lines  of  Glacial  Erosion  in  Sweden, 
Norway,  and  Finland,"  that  the  glaciation  of  the  extreme  north 
of  Europe  proceeded  from  south  to  north  ;  that  the  ice  was 
formed  on  land,  and  proceeded  seaward  in  all  directions. 

I  may  add  to  this  testimony  that  presented  by  the  North 
Cape,  Sverholt,  Nordkyn,  and  the  rest  of  the  magnificent  pre- 
cipitous headlands  that  constitute  the  characteristic  feature  of 
che  Arctic  face  of  Europe.  They  stand  forth  defiantly  as  a 
phalanx  of  giant  heralds  proclaiming  aloud  the  fallacy  of  this 
idea  of  southward  glacial  radiation  ;  and  in  concurrence  with 
the  structure  and  striation  of  the  great  glacier  troughs  that  lie 
between  them,  and  the  planed  tableland  at  their  summits,  they 
establish  the  fact  that  during  the  greatest  glaciation  of  the 
glacial  epoch  the  ice-streams  were  formed  on  land  and  flowed 
out  to  sea,  just  as  they  now  do  at  Greenland,  or  other  parts  of 


THE    "GREAT   ICE   AGE."  179 

the  world  where  the  snow  line  touches  or  nearly  approaches 
the  level  of  the  sea. 

All  such  streams  must  have  followed  the  slope  of  the  hill- 
sides upon  which  they  rested  and  down  which  they  flowed, 
and  thus  the  upper  limits  of  glaciation  afford  no  measure  what- 
ever of  the  thickness  of  the  ice  upon  "  the  low  grounds  of 
Scotland,"  or  of  any  other  glaciated  country.  As  an  example 
I  may  refer  to  Mont  Blanc.  In  climbing  this  mountain  the 
journey  from  the  lower  ice-wall  of  the  Glacier  de  Bossons  up 
to  the  bergschrund  above  the  Grand  Plateau  is  over  one  con- 
tinuous ice-field,  the  level  of  the  upper  part  of  which  is  more 
than  10,000  feet  above  its  terminal  ice- wall.  Thus,  if  we 
take  the  height  of  the  striations  or  smoothings  of  the  upper 
neve,  above  the  low  grounds  on  which  the  ice- sheets  rests,  and 
adopt  Mr.  Geikie's  reasoning,  the  lower  ice-wall  of  the  Glacier 
de  Bossons  should  be  10,000  feet  thick.  Its  actual  thickness, 
as  nearly  as  I  can  remember,  is  about  10  or  12  feet. 

Every  other  known  glacier  presents  the  same  testimony. 
The  drawing  of  a  Greenland  glacier  opposite  page  47  of  Mr. 
Geikie's  book  shows  the  same  under  arctic  conditions,  and 
where  the  ice-wall  terminates  in  the  sea. 

I  have  not  visited  the  Hebrides,  but  the  curious  analogy  of 
their  position  to  that  of  the  Lofodens  suggests  the  desirability 
of  similar  observations  to  those  I  have  made  in  the  latter.  If 
the  ice  between  the  mainland  and  the  Outer  Hebrides  was,  as 
Mr.  Geikie  maintains,  "  certainly  more  than  2000  feet  in 
thickness,"  and  this  stretched  across  to  Ireland,  besides  unit- 
ing with  the  still  thicker  ice-sheet  of  Scandinavia,  these 
islands  should  all  be  glaciated,  especially  the  smaller  rocks. 
If  I  am  right,  the  smaller  outlying  islands,  those  south  of  Barra, 
should,  like  the  corresponding  rocks  of  the  Lofodens,  display 
no  evidence  of  having  been  overswept  by  a  deep  mer  de  glace. 

I  admit  the  probability  of  an  ice-sheet  extending  as  Mr. 
Geikie  describes,  but  maintain  that  it  thinned  out  rapidly  sea- 
ward, and  there  became  a  mere  ice-floe,  such  as  now  impedes 
the  navigation  of  Smith's  Sound  and  other  portions  of  the 
Arctic  Ocean.  The  Orkneys  and  Shetlands,  with  which  I  am 
also  unacquainted,  must  afford  similar  crucial  instances,  always 
taking  into  account  the  fact  that  the  larger  islands  may  have 
been  independently  glaciated  by  the  accumulations  due  to  their 
own  glacial  resources.  It  is  the  small  rocks  standing  at  con- 
siderable distance  from  the  shores  of  larger  masses  of  land  that 
supply  the  required  test  conditions. 


ISO  SCIENCE   IX   SHOKT   CHAPTEHS. 

From  the  above  it  will  be  seen  that  I  agree  with  Mr. 
Geikie  in  regarding  the  till  as  a  moraine  profonde,  but  differ 
as  to  the  mode  and  place  of  its  deposition.  He  argues  that 
it  was  formed  under  glaciers  of  the  thickness  he  describes, 
while  their  whole  weight  rested  upon  it. 

This  appears  to  me  to  be  physically  impossible.  If  such 
glaciers  are  capable  of  eroding  solid  rocks,  the  slimy  mud  of 
their  own  deposits  could  not  possibly  have  resisted  them.  The 
only  case  where  this  might  have  happened  is  where  a  mountain- 
wall  has  blocked  the  further  downward  progress  of  a  glacier,  or 
in  pockets,  or  steep  hollows  which  a  glacier  might  have 
bridged  over  and  filled  up  ;  but  such  pockets  are  by  no  means 
the  characteristic  localities  of  till,  though  the  till  of  Switzer- 
land may  possibly  show  examples  of  the  first  case.  The  great 
depth  of  the  inland  lakes  of  Norway,  their  bottoms  being 
usually  far  below  that  of  the  present  sea-bottom,  is  in  di- 
rect contradiction  of  this.*  They  should,  before  all  places, 
be  filled  with  till,  if  the  till  were  a  ground  moraine  formed  on 
land  ;  but  all  we  know  of  them  confirms  the  belief  that  the 
glaciers  deepened  them  by  erosion  instead  of  shallowing  them 
by  deposition. 

Mr.  Geikie' s  able  defence  of  Ramsay's  theory  of  lake-basin 
erosion  is  curiously  inconsistent  with  his  arguments  in  favor  of 
the  ground  moraine. 

I  fully  concur  with  Mr.  Geikie's  arguments  against  the  ice- 
berg theory  of  the  formation  of  the  till.  This,  I  think,  he  has 
completely  refuted. 

Before  concluding  I  must  say  a  few  words  on  those  curious 
lenticular  beds  of  sand  and  gravel  in  the  till  which  appear  so 
very  puzzling.  A  simple  explanation  is  suggested  in  connec- 
tion with  the  above-sketched  view  of  the  formation  of  the  till. 
All  glaciers,  whether  in  arctic  or  temperate  climates,  are 
washed  by  streamlets  during  summer,  and  these  commonly 
terminate  in  the  form  of  a  stream  or  cascade  pouring  down  a 
moulin — a  well  bored  by  themselves  and  reaching  the  bottom 
of  the  glacier.  Now  what  must  be  the  action  of  such  a  down- 

*  The  largest  of  the  Norwegian  lakes,  the  Mjosen,  is  1550  feet 
deep,  and  its  surface  385  feet  above  the  sea  level.  Its  bottom  is 
about  1000  feet  lower  than  the  sea  outside,  or  500  to  800  feet  below 
the  bottom  of  the  Christiania  Fiord.  The  fiords,  generally  speak- 
ing, are  very  much  shallower  near  their  mouths  than  further  inland, 
as  though  their  depth  had  been  determined  by  the  thickness  of  the 
glaciers  flowing  down  them,  and  the  consequent  limits  of  flotation 
and  deposition. 


THE   BAROMETER   AND   THE   WEATHER.  181 

flow  of  water  upon  my  supposed  submarine  bed  of  till  just 
grazing  the  bottom  of  the  glacier  ?  Obviously  to  wash  away 
the  fine  clayey  particles,  and  leave  behind  the  coarser  sand  or 
gravel.  It  must  form  just  such  a  basin  or  lenticular  cavity  as 
Mr.  Geikie  describes.  The  oblong  shape  of  these,  their  longer 
axis  coinciding  with  the  general  course  of  the  glacier,  would 
be  produced  by  the  onward  progress  of  the  moulin.  The 
accordance  of  their  other  features  with  this  explanation  will  be 
seen  on  reading  Mr.  Geikie's  description  (pp.  18,19,  etc.). 

The  general  absence  of  marine  animals  and  their  occasional 
exceptional  occurrence  in  the  intercalated  beds  is  just  what 
might  be  expected  under  the  conditions  I  have  sketched.  In 
the  gloomy  subglacial  depths  of  the  sea,  drenched  with  continual 
supplies  of  fresh  water  and  cooled  below  the  freezing-point  by 
the  action  of  salt  water  on  the  ice,  ordinary  marine  life  would 
be  impossible  ;  while,  on  the  other  hand,  any  recession  of  the 
glacial  limit  would  restore  the  conditions  of  arctic  animal  life, 
to  be  again  obliterated  with  the  renewed  outward  growth  of 
the  floating  skirts  of  the  inland  ice-mantle. 

But  I  must  now  refrain  from  the  further  discussion  of  these 
and  other  collateral  details,  but  hope  to  return  to  them  in 
another  paper. 

In  "  Through  Norway  with  Ladies"  I  have  touched  lightly 
upon  some  of  these,  and  have  more  particularly  described  some 
curious  and  very  extensive  evidences  of  secondary  glaciation 
that  quite  escaped  my  attention  on  my  first  visit,  and  which, 
too,  have  been  equally  overlooked  by  other  observers.  In  the 
above  I  have  endeavored  to  keep  as  nearly  as  possible  to  the 
main  subject  of  the  origin  of  the  till  and  the  character  of  the 
ancient  ice-sheet. 


CHAPTER  XXIV. 

THE    BAROMETER    AND    THE    WEATHER. 

THE  barometer  was  invented  by  Torricelli,  an  Italian  philos- 
opher of  the  seventeenth  century.  It  consists  essentially  of  a 
long  tube  open  at  one  end  and  closed  at  the  other,  and  partly 
filled  with  mercury  ;  but  instead  of  being  filled  like  ordinary 
vessels,  with  the  open  end  or  mouth  upward  and  the  closed 


182  SCIENCE   IX   SHORT   CHAPTEBS. 

end  or  bottom  downward,  the  barometer-tube  is  inverted,  and 
has  its  open  mouth  downward.  This  open  mouth  is  either 
dipped  into  a  little  cup  of  mercury  or  bent  a  little  upward. 

Why  does  not  the  mercury  run  out  of  this  lower  open  end 
and  overflow  the  little  cup  when  it  is  inverted  after  being  filled  ? 

The  answer  to  this  question  includes  the  whole  mystery  and 
principle  of  the  barometer.  The  mercury  does  not  fall  down 
because  something  pushes  it  up  and  supports  it  with  a  certain 
degree  of  pressure,  and  that  something  is  the  atmosphere  which 
extends  all  round  the  world,  and  presses  downward  and  side- 
way  and  upward — in  every  direction,  in  fact — with  a  force 
equal  to  its  weight,  i.e.  with  a  pressure  equal  to  about  15  Ibs. 
on  every  square  inch.  A  column  or  perpendicular  square  stick 
of  air  one  inch  thick  each  way,  and  extending  from  the  surface 
of  the  sea  up  to  the  top  of  the  atmosphere,  weighs  about  15 
Ibs. ;  other  columns  or  sticks  next  to  it  on  all  sides  weigh  the 
same,  and  so  on  with  every  portion  ;  and  all  these  are  forever 
squeezing  down  and  against  each  other,  and,  being  fluid,  trans- 
mit their  pressure  in  every  direction,  and  against  the  earth  and 
everything  upon  it,  and  therefore  upon  the  mercury  of  the 
barometer-tube. 

We  have  supposed  the  air  to  be  made  up  of  columns  or 
sticks  of  air  one  inch  each  way,  but  might  have  taken  any  other 
size,  and  the  weight  and  pressure  would  be  proportionate. 
Now  mercury,  bulk  for  bulk,  is  so  much  heavier  than  air  that 
a  stick  or  column  of  this  liquid  metal  about  30  inches  high 
weighs  as  much  as  a  stick  or  column  of  air  of  same  thickness 
reaching  from  the  surface  of  the  earth  to  the  top  of  the  atmos- 
phere ;  therefore,  the  30-inch  stick  of  mercury  balances  the 
pressure  of  the  many  miles  of  atmosphere,  and  is  supported  by 
it.  Thus  the  column  of  mercury  may  be  used  to  counter- 
balance the  atmosphere  and  show  us  its  weight  ;  and  such  a 
column  of  mercury  is  a  barometer,  or  "  weight  measure." 
The  word  barometer  is  compounded  of  the  two  Greek  word* 
baros,  weight,  and  metron,  a  measure. 

If  you  take  a  glass  tube  a  yard  long,  stopped  at  one  end  and 
open  at  the  other,  fill  it  with  mercury,  stop  the  open  end  with 
your  thumb,  then  invert  the  tube  and  just  dip  the  open  end  in 
a  little  cup  of  mercury,  some  of  the  mercury  in  the  tube 
will  fall  into  the  cup,  but  not  all  ;  only  6  inches  will  fall,  the 
other  30  inches  will  remain,  with  an  empty  space  between  it 
and  the  stopped  end  of  the  tube.  When  you  have  done  this 
you  will  have  made  a  rude  barometer.  If  you  prop  up  the 


THE    BAROMETER    AXI)    THE    WEATHER.  183 

tub6,  and  watch  it  carefully  from  day  to  day,  you  will  find  that 
the  height  of  the  column  of  mercury  will  continually  vary.  If 
von  live  at  the  sea-level,  or  thereabouts,  it  will  sometimes  rise 
more  than  30  inches  above  the  level  of  the  mercury  in  the  cup, 
and  frequently  fall  below  that  height.  If  you  live  on  the  top 
*  of  a  high  mountain,  or  on  any  high  ground,  it  will  never 
reach  30  inches,  will  still  be  variable,  its  average  height  less 
than  if  you  lived  on  lower  ground  ;  and  the  higher  you  got  he 
less  will  be  this  average  height  of  the  mercury. 

The  reason  of  this  is  easily  understood.  When  we  ascend  a 
mountain  we  leave  some  portion  of  the  atmosphere  below  us, 
and  of  course  less  remains  above  ;  this  smaller  quantity  must 
have  less  weight  and  press  the  mercury  less  forcibly.  If  the 
barometer  tells  the  truth,  it  must  show  this  difference  ;  and  it 
does  so  with  such  accuracy  that  by  means  of  a  barometer,  or 
rather  of  two  barometers — one  at  the  foot  of  the  mountain  and 
one  on  its  summit — we  may,  by  their  difference,  measure  the 
height  of  the  mountain  provided  we  know  the  rules  for  making 
the  requisite  calculations. 

The  old-fashioned  barometer,  with  a  large  dial-face  and 
hands  like  a  clock,  is  called  the  **  wheel  barometer,"  because  the 
mercury,  in  rising  and  falling,  moves  a  little  glass  float  resting 
upon  the  mercury  of  the  open  bent  end  of  the  tube  ;  to  this 
float  and  its  counterpoise  a  fine  cord  is  attached,  and  this  cord 
goes  round  a  little  grooved  wheel  to  which  the  hands  are 
attached.  Thus  the  rising  and  falling  of  the  mercury  moves 
the  float,  the  float-cord  turns  the  wheel,  and  the  wheel  moves 
the  hands  that  point  to  the  words  and  figures  on  the  dial. 
When  this  hand  moves  toward  the  right,  or  in  the  direction 
of  an  advancing  clock-hand,  the  barometer  is  rising  ;  when  it 
goes  backward,  or  opposite  to  the  clock-hand  movement,  the 
mercury  is  falling.  By  opening  the  little  door  at  the  back  of 
such  a  barometer,  the  above-described  mechanism  is  seen.  In 
doing  this,  or  otherwise  moving  your  barometer,  be  careful 
always  to  keep  it  upright. 

It  sometimes  happens  to  these  wheel  barometers  that  they 
suddenly  cease  to  act  ;  and  in  most  cases  the  owner  of  the 
barometer  may  save  the  trouble  and  expense  of  sending  it  to 
the  optician  by  observing  whether  the  cord  has  slipped  from 
the  little  wheel,  and  if  so,  simply  replacing  it  in  the  groove 
upon  its  edge.  If,  however,  the  mischief  is  caused  by  the 
tube  being  broken,  which  is  seen  at  once  by  the  mercury  having 
run  out,  the  case  is  serious,  and  demands  professional  aid. 


8  SCIENCE    IN    SHOUT    CHATTERS. 

The  upright  barometer,  which  shows  the  surface  of  the  mer- 
cury itself,  is  the  most  accurate  instrument,  provided  it  is  care- 
fully read.  This  form  of  instrument  is  always  used  in  meteor- 
ological observatories,  where  minute  corrections  are  made  for 
the  expansion  and  contraction  which  variations  of  temperature 
produce  upon  the  length  of  the  mercury  without  altering  its 
weight,  and  for  the  small  fluctuations  in  the  level  of  the  mer- 
cury cistern.  With  such  instruments,  fitted  with  an  appara- 
tus called  a  "  vernier,"  the  height  of  the  mercury  may  be  read 
to  hundrcdths  of  an  inch. 

The  necessity  for  the  30  inches  of  mercury  renders  the 
mercurial  barometer  a  rather  cumbrous  instrument  :  it  must  be 
more  than  30  inches  long,  and  is  liable  to  derangement  from 
the  spilling  of  the  mercury.  On  this  account  portable  barom- 
eters of  totally  different  construction  have  been  invented.  The 
"  aneroid"  barometer  is  one  of  these — the  only  one  that  is 
practically  used  to  any  extent.  It  contains  a  metal  box  partly 
rilled  with  air  ;  one  face  of  the  box  is  corrugated,  and  so  thin 
that  it  can  rise  and  fall  like  a  stretched  covering  of  india-rubber. 
As  the  pressure  of  the  outside  air  varies  it  does  rise  and  fall, 
and  by  a  beautifully-delicate  apparatus  this  rising  and  falling  is 
magnified  and  represented  upon  the  dial.  Such  barometers  are 
made  small  enough  to  be  carried  in  the  pocket,  and  are  very 
useful  for  measuring  the  heights  of  mountains  ;  but  they  are 
not  quite  so  accurate  as  the  mercurial  barometer,  and  are 
therefore  not  used  for  rigidly  scientific  measurements  ;  but 
for  all  ordinary  purposes  they  are  accurate  enough,  provided 
they  are  occasionally  compared  with  a  standard  mercurial 
barometer,  and  adjusted  by  means  of  the  watch-key  axis  pro- 
vided for  that  purpose,  and  seen  on  the  back  of  the  instrument. 
They  are  sufficiently  delicate  to  tell  the  traveller  in  a  railway 
whether  he  is  ascending  or  descending  an  incline,  and  will  in- 
dicate the  difference  of  height  between  the  upper  and  lower 
rooms  of  a  three-story  house.  With  due  allowance  for  varia- 
tions of  level,  the  traveller  may  use  them  as  weather  indica- 
tors ;  especially  as  it  is  the  direction  in  which  the  barometer 
is  moving  (whether  rising  or  falling)  rather  than  its  absolute 
height  that  indicates  changes  of  weather.  Thus,  by  placing 
the  aneroid  in  his  room  on  reaching  his  hotel  at  night,  care- 
fully marking  its  height  then  and  there,  and  comparing  this  with 
another  observation  made  on  the  following  morning,  he  may 
use  it  as  a  weather-glass  in  spite  of  hill  and  dale. 

Water  barometers  have  been  made  on  the  same  principle  aa 


THE   BAROMETER   AND  THE   WEATHER.  185 

the  mercury  barometer  ;  but  as  water  is  13-J-  times  lighter, 
bulk  for  bulk,  than  mercury,  the  height  of  the  column  must  be 
13^  times  30  inches,  or,  allowing  for  variations,  not  less  than 
34  feet.  This,  of  course,  is  very  cumbrous  ;  the  evaporation 
of  the  water  presents  another  considerable  difficulty,*  still  such 
a  barometer  is  a  very  interesting  instrument,  as  it  shows  the 
atmospheric  fluctuations  on  13^  times  the  scale  of  the  ordinary 
barometer.  A  range  of  about  five  feet  is  thus  obtained  ;  and 
not  only  the  great  waves,  but  even  the  comparatively  small 
ripples  of  the  atmospheric  ocean  are  displayed'  by  it.  In 
stormy  weather  it  may  be  seen  to  rise  and  fall  and  pulsate  like  a 
living  creature,  so  sensitively  does  it  respond  to  every  atmos- 
pheric fluctuation. 

But  why  should  the  height  of  the  barometer  vary  while  it 
remains  in  the  same  place  ? 

If  the  quantity  of  air  surrounding  the  earth  remains  the 
same,  and  if  the  barometer  measures  its  weight  correctly,  why 
should  the  barometer  vary  ? 

Does  the  atmosphere  grow  bigger  and  smaller,  lighter  and 
heavier,  from  time  to  time  ? 

These  are  fair  questions,  and  they  bring  us  at  once  to  some 
of  the  chief  uses  of  the  barometer.  The  atmosphere  is  a  great 
gaseous  ocean  surrounding  the  earth,  and  we  are  creeping  about 
on  the  bottom  of  this  ocean.  It  has  its  tides  and  billows 
and  whirling  eddies,  but  all  these  are  vastly  greater  than  those 
of  the  watery  ocean.  At  one  time  we  are  under  the  crest  or 
rounded  portion  of  a  mighty  atmospheric  wave,  at  another  the 
hollow  between  two  such  waves  is  over  our  heads,  and  thus  the 
depth  of  atmosphere,  or  quantity  of  air,  above  us  is  variable. 
This  variation  is  the  combined  result  of  many  co-operating 
causes.  In  the  first  place  there  are  great  atmospheric  tides, 
caused,  like  those  of  the  sea,  by  the  attraction  of  the  sun  and 
moon  ;  but  these  do  not  directly  affect  the  barometer,  because 
the  attracting  body  supports  whatever  it  lifts.  Variations  of 
temperature  also  produce  important  fluctuations  in  the  height 
and  density  of  the  atmosphere,  some  of  which  are  indicated  by 
the  barometer — others  are  not.  Thus  a  mere  expansion  or 
contraction  of  dry  air,  increasing  the  depth  or  the  density  of 
the  atmospheric  ocean,  would  not  affect  the  barometer,  as 
mere  expansion  and  contraction  only  alter  the  bulk  without 
affecting  the  weight  of  the  air.  But  our  atmosphere  consists 

*  This  has  been  recently  overcome  to  a  great  extent  by  using 
glycerine  instead  of  water. 


18G  SCIENCE   IX   SHOUT    CHAPTERS. 

not  only  of  the  permanent  gases,  nitrogen  and  oxygen  5  it  con- 
tains, besides  these  and  carbonic  acid,  a  considerable  quantity 
of  gaseous  matter,  which  is  not  permanent,  but  which  may  be 
a  gas  at  one  moment — contributing  its  whole  weight  to  that  of 
the  general  atmosphere — and  at  another  moment  some  of  it 
may  be  condensed  into  liquid  particles  that  fall  through  it 
more  or  less  rapidly,  and  thus  contribute  nothing  to  its  weight. 
What,  then  is  this  variable  constituent  that  sometimes  adds 
to  the  weight  of  the  atmosphere  and  the  consequent  height  of 
the  barometer,  and  at  others  may  suddenly  cease  to  afford  its 
full  contribution  to  atmospheric  pressure  ? 

It  is  simply  water,  which,  as  we  all  know,  exists  as  solid, 
liquid,  or  gas,  according  to  the  temperature  and  pressure  to 
which  it  is  exposed.  We  all  know  that  steam  when  it  first 
issues  from  the  spout  of  a  tea-kettle  is  a  transparent  gas,  or 
true  vapor,  but  that  presently,  by  contact  with  the  cool  air,  it 
becomes  white,  cloudy  matter,  or  minute  particles  of  water  ; 
and  that,  if  these  are  still  further  cooled,  they  will  become 
hoar-frost  or  snow,  or  solid  ice.  Artificial  hoar-frost  and  snow 
may  be  formed  by  throwing  a  jet  of  steam  into  very  cold, 
frosty  air.  If  you  take  a  tin  canister  or  other  metal  vessel,  fill 
it  with  a  mixture  of  salt  with  pounded  ice  or  snow,  and  then 
hold  the  outside  of  the  canister  against  a  jet  of  steam,  such  as 
issues  from  the  spout  of  a  tea-kettle,  a  snowy  deposit  of  hoar- 
frost will  coat  the  outside  of  the  tin.  Now  let  us  consider 
what  takes  place  when  a  warm  southwesterly  wind,  that  lias 
swept  over  the  tropical  regions  of  the  Atlantic  ocean,  reaches 
the  comparatively  cold  shores  of  Britain.  It  is  cooled  thereby, 
and  some  of  its  gaseous  water  is  condensed — forming  mists, 
clouds,  rain,  hoar-frost,  or  snow.  The  greater  part  of  this 
forms  and  falls  on  the  western  coasts,  on  Cornwall,  Ireland, 
the  Western  Highlands  of  Scotland.  Ireland  gets  the  lion's 
share  of  this  humidity,  and  hence  her  *'  emerald  "  verdure. 
The  western  slope  of  a  mountain,  in  like  manner,  receives 
more  rain  than  the  side  facing  the  east. 

How  does  this  condensation  affect  the  barometer  ? 

It  must  evidently  cause  it  to  fall,  inasmuch  as  the  air  must 
be  lightened  to  the  exact  extent  of  all  that  is  taken  out  of  it 
and  precipitated.  But  the  precipitation  is  not  completed  imme- 
diately the  condensation  occurs.  It  takes  some  time  for  the 
minute  cloudy  particles  to  gather  into  rain-drops  and  fall  to  the 
earth,  while  the  effect  of  the  condensation  upon  the  barometer 
is  instantaneous  ;  the  air  begins  to  grow  lighter  immediately 


THE   BAROMETER   AND   THE   WEATHER.  187 

the  gas  is  converted  into  cloud  or  mist,  and  the  barometer  falls 
just  at  the  same  time  and  same  rate  as  this  is  produced  ;  but 
the  rain  comes  some  time  afterward.  Hence  the  use  of  the 
barometer  as  a  * '  weather  glass. ' '  When  intelligently  and  prop- 
erly used  it  is  very  valuable  in  this  capacity  ;  but,  like  most 
things,  it  may  easily  be  misunderstood  and  misused. 

The  most  common  error  in  the  use  of  the  barometer  is  that 
to  which  people  are  naturally  led  by  the  words  engraved  upon 
it,  "  Stormy,  Much  Rain,  Rain,  Change,  Fair,  Set  Fair,"  etc. 
A  direct  and  absolute  blunder  or  falsehood  is  usually  short- 
lived, and  deceives  but  few  people  ;  but  a  false  statement, 
with  a  certain  amount  of  superficial  truth,  may  survive  for 
ages,  and  deceive  whole  generations.  Now  this  latter  is  just 
the  character  of  the  weather  signs  that  are  engraved  on  our 
popular  barometers  ;  they  are  unsound  and  deceptive,  but  not 
utterly  baseless. 

Stormy,  Much  Rain,  and  Rain  are  marked  against  the  low 
readings  of  the  barometer,  and  Very  Dry,  Set  Fair,  and  Fair 
against  the  higher  readings.  A  low  barometer  is  not  a  reliable 
sign  of  wet  or  stormy  weather,  neither  is  a  high  barometer  to 
be  depended  upon  for  expecting  fine  weather  ;  and  yet  it  is 
true  that  we  are  more  likely  to  have  fine  weather  with  a  high 
than  with  a  low  barometer,  and  also  the  liability  to  rain  and 
storms  is  greater  with  a  low  than  with  a  high  barometer. 

The  best  indications  of  the  weather  are  those  derived  from 
the  direction  in  which  the  barometer  is  moving — whether  rising 
or  falling — rather  than  its  mere  absolute  height. 

A  sudden  and  considerable  fall  is  an  almost  certain  indica- 
tion of  strong  winds  and  stormy  weather.  This  is  the  most 
reliable  of  the  prophetic  warnings  of  the  barometer,  and  the 
most  useful,  inasmuch  as  it  affords  the  mariner  just  the  warn- 
ing he  requires  when  lying  off  a  dangerous  coast,  or  otherwise 
in  peril  by  a  coming  gale.  Many  a  good  ship  has  been  saved 
by  intelligent  attention  to  the  barometer,  and  by  running  into 
haven,  or  away  from  a  rocky  shore,  when  the  barometer  has 
fallen  with  unusual  rapidity. 

The  next  in  order  of  reliability  is  the  indication  afforded 
by  a  steady  and  continuous  fall  after  a  long  period  of  fine 
weather.  This  is  usually  followed  by  a  decided  change  of 
(veather,  and  the  greater  the  fall  the  more  violent  the  change. 
If  the  fall  is  slow,  and  continues  steadily  for  a  long  time,  the 
change  is  likely  to  be  less  sudden  but  more  permanent,  i.e.  the 
rain  will  probably  arrive  after  some  time)  and  then  continue 
steadily  for  a  long  period. 


188  SCIENCE   IX    SHORT   CHAPTERS. 

In  like  manner,  a  steady,  regular  rise,  going  on  for  some 
days  in  the  midst  of  wet  weather,  may  be  regarded  as  a  hope- 
ful indication  of  coming  continuous  fine  weather — the  more 
gradual  and  steady  the  lise,  the  longer  is  the  fine  weather  likely 
to  last. 

The  least  reliable  of  all  the  barometric  changes  is  a  sudden 
rise.  In  winter  it  may  be  followed  by  hard  and  sudden  frost, 
in  summer  by  sultry  weather  and  thunder-storms.  All  that 
may  be  safely  said  of  such  sudden  rise  is,  that  it  indicates  a 
change  of  some  sort. 

The  barometer  is  usually  high  with  N.E.  winds,  and  low 
with  S.  W.  winds.  The  preceding  explanations  show  the  reason 
of  this.  In  a  given  place  the  extreme  range  of  variation  is 
from  2  to  2-J  inches. 

It  has  been  proposed  that  the  following  rules  should  be 
engraved  on  barometer-plates  instead  of  the  usual  words  : 

1st.  Generally,  the  rising  of  the  mercury  indicates  the 
approach  of  fair  weather  ;  the  falling  of  it  shows  the  approach 
of  foul  weather. 

2d.  In  sultry  weather,  the  fall  of  the  barometer  indicates 
coming  thunder.  In  winter,  the  rise  of  the  mercury  indicates 
frost.  In  frost,  its  fall  indicates  thaw,  and  its  rise  indicates 
snow. 

3d.  Whatever  change  in  the  weather  suddenly  follows  a 
change  in  the  barometer,  may  be  expected  to  last  but  a  short 
time. 

4th.  If  fair  weather  continues  for  several  days  during  which 
the  mercury  continually  falls,  a  long  succession  of  foul 
weather  will  probably  ensue  ;  and  again,  if  foul  weather  con- 
tinues for  several  days  while  the  mercury  continually  rises,  a 
long  succession  of  fair  weather  will  probably  follow. 

5th.  A  fluctuating  and  unsettled  state  of  the  mercurial 
column  indicates  changeable  weather. 

As  the  barometer  is  subject  to  slight  diurnal  variations, 
irrespective  of  those  atmospheric  changes  which  affect  the 
weather,  it  is  desirable  in  making  comparative  observations  to 
do  so  at  fixed  hours  of  the  day.  Nine  or  ten  in  the  morning 
and  same  hour  in  the  evening  are  good  times  for  observations 
that  are  to  be  recorded.  These  are  about  the  hours  of  daily 
maxima  or  highest  readings  due  to  regular  diurnal  variation. 

The  true  reading  of  the  barometer  is  the  height  at  which  it 
would  stand  if  placed  at  the  level  of  the  sea  at  high  tide  ;  but, 
jus  barometers  arc  always  placed  more  or  less  above  this  level, 


1HE   HA11031ETER    AXD   THE    WEATHER.  ISO 

a  correction  for  elevation  is  necessary.  When  the  height  of 
the  place  is  known  this  correction  may  be  made  by  adding  one 
tenth  of  an  inch  to  the  actual  reading  for  every  85  feet  of 
elevation  up  to  510  feet  ;  the  same  for  every  90  feet  between 
510  and  1140  feet,  for  every  95  feet  between  1140  and  1900 
feet,  and  for  every  100  feet  above  this  and  within  our  moun- 
tain limits.  This  simple  and  easy  rule  is  sufficiently  accurate 
for  practical  purposes.  Thus,  a  barometer  on  Bray  Head,  or 
any  place  800  feet  above  the  sea,  would  require  a  correction  of 
six  tenths  for  the  first  510  feet,  and  a  little  more  than  three 
tenths  more  for  the  remaining  290  feet.  Therefore,  if  such 
a  barometer  registered  the  pressure  at  92T*ff,  the  proper  sea- 
level  reading  would  be  a  little  above  30  inches. 

The  most  important  prognostications  of  the  barometer  are 
those  afforded  by  what  is  called  the  **  barometric  gradient  or 
incline,"  showing  the  up-hill  and  down-hill  direction  of  the 
atmospheric  inequalities  ;  but  this  can  only  be  ascertained  by 
comparing  the  state  of  the  barometer  at  different  stations  at 
the  same  time.  Thus,  if  the  barometer  is  one  fourth  of  an 
inch  higher  at  Dublin  than  at  Galway,  and  the  intermediate 
stations  show  intermediate  heights,  there  must  be  an  atmos- 
pheric down-hill  gradient  from  Dublin  to  Galway  ;  Dublin 
must  be  under  the  upper  and  Galway  under  the  lower  portion 
of  a  great  atmospheric  wave  or  current.  It  is  evident  that 
when  there  is  thus  more  air  over  Dublin  than  over  Galway, 
there  must  follow  (if  nothing  else  interferes)  a  flow  of  air  from 
Dublin  toward  Galway.  It  is  also  evident  that,  in  order  to 
tell  what  else  may  interfere,  we  must  know  the  atmospheric 
gradients  beyond  and  around  both  Dublin  and  Galway,  and 
for  considerable  distances. 

We  are  now  beginning  to  obtain  such  information  by  organ- 
izing meteorological  stations  and  observatories,  and  transmit- 
ting the  results  of  simultaneous  observations  by  means  of  the 
electric  telegraph  to  certain  head-quarters. 

The  subject  is  occupying  much  attention,  and  the  managers 
of  those  splendid  monuments  of  British  energy — our  daily 
newspapers — are  publishing  daily  weather  charts,  and  there- 
fore a  few  simple  explanations  of  the  origin,  nature,  and  sig- 
nificance of  such  charts  will  doubtless  be  appreciated  by  our 
readers. 

The  grand  modern  improvement  of  the  barometer,  the  ther- 
mometer, the  anemometer,  the  pluviometer,  etc.,  is  that  of 
making  them  "  self -registering."  \Vc  are  told  that  Cadmus 


190  SCIENCE   IN   SHOET   CHAPTERS. 

invented  the  art  of  writing,  and  we  honor  his  memory  accord- 
ingly. But  he  ventured  no  further  than  teaching  human 
beings  to  write.  Modern  meteorologists  have  gone  much 
further  ;  they  have  taught  the  winds  and  the  rains  and  the 
subtle  heavings  of  the  invisible  air  to  keep  their  own  diaries, 
to  write  their  own  histories  on  paper  that  is  laid  before  them, 
with  pencils  that  are  placed  in  their  tieshless,  boneless,  and 
shapeless  fingers.  This  achievement  is  wrought  by  compara- 
tively simple  means.  The  paper  is  wound  upon  an  upright 
drum  or  cylinder,  and  this  cylinder  is  made  to  revolve  by 
clock-work,  in  such  a  mannner  that  a  certain  breadth  travels  on 
during  the  twenty-four  hours.  This  breadth  of  paper  is  divided 
by  vertical  lines  into  twenty-four  parts,  each  of  which  passes 
onward  in*  one  hour.  Connected  with  the  barometer  is  a 
pencil  which,  by  means  of  a  spring,  pi  esses  lightly  upon  the 
revolving  sheet,  and  this  pencil,  while  thus  pressing,  rises  and 
falls  with  the  mercnry.  It  is  obvious  that,  in  this  manner,  a 
line  will  be  drawn  as  the  paper  moves.  If  the  mercury  is 
stationary,  the  line  will  be  horizontal  —  only  indicating  the 
movement  of  the  drum  ;  if  the  mercury  tails,  the  line  will 
slope  downward  ;  if  it  rises,  it  will  incline  upward.  By  rul- 
ing horizontal  lines  upon  the  paper,  representing  inches, 
tenths,  and  smaller  fractions  if  desired,  the  whole  history  of 
the  barometrical  movements  will  be  graphically  recorded  by  the 
waving  or  zigzag  lines  thus  drawn  by  the  atmosphere  itself. 

The  subjoined  copy  of  the  Daily  Telegraph  Barometer  Chart 
represents,  on  a  small  scale,  a  four  days'  history  of  barometrical 
movements  : 

The  large  figures  at  the  side  (29  and  30)  represent  inches  ; 
the  smaller  figures  tenths  of  inches. 

The  pressure  of  the  wind  is  similarly  pictured  by  means  of  a 
large  vane  which  turns  with  the  wind,  and  to  the  windward 
face  of  which  a  flat  board  or  plate  of  metal,  one  foot  square,  is 
attached  perpendicularly.  As  the  wind  strikes  this  it  presses 
against  it  with  a  force  corresponding  to  a  certain  number  of 
pounds,  ounces,  and  fractions  of  an  ounce.  A  spring  like 
that  of  an  ordinary  spring  letter-balance  is  compressed  in  pro- 
portion to  this  pressure.  This  movement  of  the  spring  is 
transmitted  mechanically  to  another  pencil  like  the  above 
described,  working  against  the  same  drum  ;  thus  another  his- 
tory  is  'written  on  the  same  paper — the  horizontal  lines  now 
representing  fractions  of  pounds  of  pressure,  instead  of  frac- 
tions of  inches  of  mercury. 


THE    BAROMETER   AXD    THE    WEATHER. 


191 


It  has  been  found  that  if  a  semi-globular  cup  of  thin  metal 
is  exposed  to  the  wind,  the  pressure  upon  the  round  or  convex 
side  of  the  hemisphere  is  equal  to  two  thirds  of  that  upon  the 
hollow  or  concave  side.  By  placing  four  such  cups  upon 
cross-arms,  and  the  arms  on  a  pivot,  the  wind,  from  whatever 
quarter  it  may  come,  will  always  blow  them  round  with  their  con- 
vex faces  foremost  ;  and  they  will  move  with  one  third  of  the 
actual  velocity  of  the  wind.  By  a  simple  clock-work  arrange- 
ment, these  arms  move  another  pencil,  in  such  a  manner  that 
it  strikes  the  paper  hammer- fashion  every  time  the  wind  has 
completed  a  journey  of  one  mile,  or  other  given  distance  ;  and 
thus  a  series  of  dots  upon  the  revolving  paper  records  the 
velocity  of  the  wind  according  to  their  distances  apart.  As 
the  pressure  of  the  wind  is  governed  by  two  factors — viz.,  the 


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density  and  velocity  of  the  moving  air — the  relations  between 
the  barometer  curve,  the  pressure  curve  and  the  velocity  dots 
are  very  interesting. 

The  direction  of  the  wind  is  written  by  a  pencil  fixed  to  a 
quick  worm — a  screw  thread  upon  the  axis  of  the  vane.  As 
the  vane^turns  round — N.,  E.,  S.,  or  W. — it  screws  the  pencil 
up  or  down,  and  thus  the  horizontal  lines  first  described  as 
registering  tenths  of  inches  of  barometric  pressure  do  dutv  as 
showing  the  points  of  the  compass  from  which  the  wind  is 
blowing  ;  and,  by  reference  to  the  zigzag  line  drawn  by  this 
pencil  of  the  wind,  its  direction  at  any  particular  time  of  day 
may  be  ascertained  as  certified  by  its  own  sign  manual. 

The  wind-gauge  is  called  an  anemometer.  Connected  with 
this  is  the  pluviometer,  or  rain-gauge— an  upright  vessel  with 


192  SCIENCE   IX   SHORT   CHAPTERS. 

an  open  mouth  of  measured  area — say  100  square  inches. 
This  receives  the  rain  that  falls.  By  means  of  a  pipe  the 
water  is  conveyed  to  a  vessel  having  a  surface  of — say  one 
square  inch.  By  this  arrangement,  when  sufficient  rain  has 
fallen  to  cover  the  surface  of  the  earth  to  the  depth  of  one 
hundredth  of  an  inch,  the  little  vessel  below  will  contain  water 
one  inch  in  depth.  By  balancing  this  vessel  at  the  end  of  a 
Jong  arm,  it  is  made  to  preponderate  gradually  as  the  weight 
of  water  it  receives  increases,  and  finally,  when  filled,  it  tips 
over  altogether,  empties  itself,  and  then  rises  to  its  starting 
place  in  equilibrium.  To  the  other  end  of  this  arm  a  pencil  is 
attached,  which  inscribes  all  these  movements  on  the  revolv- 
ing paper,  and  thus  tells  the  nistory  of  the  rainfall.  The  line 
is  zigzag  while  the  rain  is  Jailing,  and  horizontal  while  the 
weather  is  fair.  The  amount  of  inclination  of  the  zigzag  line 
measures  the  depth  of  rain  by  means  of  the  same  ruled  lines 
on  the  paper  as  measure  the  height  of  the  barometer,  etc. 
Every  time  the  measuring  vessel  tips  over  a  perpendicular  line 
is  drawn,  and  the  pencil  resumes  its  starting  level.  The 
papers  containing  these  autographs  of  the  elements  may,  of 
course,  be  kept,  as  permanent  records  for  reference  whenever 
needed,  or  the  results  may  be  tabulated  in  other  forms. 

There  are  many  modifications  in  the  details  of  these  self- 
registering  instruments.  In  some  of  them  photography  is 
made  to  do  a  part  of  the  work.  The  above  description  indi- 
cates the  main  principles  of  their  construction,  without  attempt- 
ing to  enter  upon  minute  details. 

Meteorological  observatories  are  provided  with  these  instru- 
ments, and  all  nations  worthy  of  the  name  of  civilized  co-oper- 
ate with  more  or  less  efficiency  in  providing  and  endowing 
such  establishments.  They  are  placed  in  suitable  localities,  and 
communicate  with  each  other,  and  with  certain  head-quarters, 
by  means  of  the  electric  telegraph.  One  of  these  head- quar- 
ters is  the  Meteorological  Office,  at  No.  116  Victoria  Stieet, 
Westminster,  S.W.,  which  daily  receives  the  results  of  the 
observations  taken  at  about  fifty  stations  on  the  British  Islands 
and  the  Continent.  The  chief  observations  are  made  simul- 
taneously— at  8  A.M. — and  telegraphed  in  cipher  to  London, 
where  they  usually  arrive  before  10  A.M.  As  they  come  in 
they  are  marked  down  in  their  proper  places  upon  a  large 
chart,  and  when  this  chart  is  sufficiently  completed,  a  con- 
densed or  abstract  copy  is  made  containing  as  much  informa- 
tion as  may  be  included  in  the  small  newspaper  charts.  This 


THE  BAROMETER  AND  THE  WEATHER.      193 

is  copied  mechanically  on  a  reduced  scale  on  a  slab  on  which 
the  outline  chart  has  been  already  engraved.  This  engraving 
completed,  casts  are  made  in  fusible  metal  with  the  black  lines 
in  relief,  for  printing  with  ordinary  type,  and  the  casts  are  set 
up  with  the  ordinary  newspaper  types,  and  printed  with  the 
letter-press  matter. 

The  engravings  overleaf  are  taken  from  two  of  the  news- 
paper weather  charts  for  the  dates  of  October  5th,  and  6th. 
They  are  enlarged  and  printed  more  clearly  than  the  originals, 
with  an  explanation  of  signs  at  foot  of  the  charts. 

It  will  be  observed  that,  in  the  chart  for  October  5th,  an 
isobar  of  29s  runs  up  in  a  N.  E.  direction  from  between  the 
Orkney  and  Shetland  islands,  crosses  the  North  Sea,  strikes  the 
coast  of  Norway  near  Bergen,  and  then  proceeds  onward 
toward  Thron  hjemd.  An  isobar  of  29*  5  crosses  Scotland, 
following  very  nearly  the  line  of  the  Grampians,  enters  the 
North  Sea  about  Aberdeen,  and  crosses  to  Christiansund  ; 
then  runs  up  the  Skagar  Rack  and  Ghristiania  Fiord  toward 
Ohristiania.  Another  isobar  of  29*8  crosses  Ireland  through 
Connaught  to  Dublin,  onward  across  England  by  Liverpool 
and  the  Humber,  over  the  North  Sea,  and  through  Schleswig  to 
the  Baltic.  These  three  are  nearly  parallel  ;  but  now  we  find 
another  isobar — that  of  30*2 — taking  quite  a  different  course, 
by  starting  from  the  Bay  of  Biscay  about  Nantes  ;  running  on 
toward  Paris  and  Strasbourg,  and  then  bending  sharp  round, 
as  though  frightened  by  the  Germans,  and  retreating  to  the 
Gulf  of  Lyons  by  an  opposite  course  to  that  on  which  it  started. 
On  the  following  day  all  has  changed  ;  the  northern  isobars  are 
running  down  south-eastward  instead  of  north-east,  and  are 
remarkably  parallel.  In  the  left-hand  upper  corner  of  this 
chart  is  a  note  that  "  our  west,  north,  and  eastern  coasts  were 
warned  yesterday.1'1  Why  was  this  ?  It  was  mainly  because  the 
barometric  gradient  or  incline  was  so  steep.  On  the  5th  there 
was  one  inch  of  difference  between  the  Orkneys  and  the  Bay 
of  Biscay,  or  between  Bergen  and  Paris,  while  the  barometer 
was  still  falling  in  Norway  and  at  the  same  moment  rising  in 
Ireland  and  France.  On  the  following  day  these  movements 
culminated  in  a  gradient  of  1*4 — nearly  one  and  a  half  inches 
— between  Cornwall  and  the  ancient  capital  of  Norway. 

What  must  follow  from  this  condition  of  the  atmosphere  ? 
Clearly  a  great  flow  or  rush  of  air  from  the  south  toward  the 
comparatively  vacuous  regions  of  the  north.  The  gases  of  our 
atmosphere,  like  the  waters  of  the  ocean,  are  always  struggling 


194 


SCIEJNUE 


SHORT   CHAPTERS. 


WEATHER  CHART,  OCTOBER  5,  1875. 


EXPLANATION  OF  WEATHER  CHART. 

In  these  charts  the  state  of  the  sea— whether  "rough,"  "smooth,"  "moderate," 
"slight,"  etc.,  is  marked  in  capital  letters;  and  the  state  of  the  weather— as  "clear," 
"dull,"  "cloudy,"  "showery,"  etc.,  in  small  letters.  The  direction  of  the  wind  is 
indicated  by  the  arrow«.  Unlike  the  arrows  of  a  vane,  these  do  not  point  toward 
the  direction  from  which  the  wind  is  coming,  hut  are  flying  arrows  represented  as 
moving  with  the  wind,  and  consequently  pointing  to  where  the  wind  is  going.  The 
force  of  the  wind  is  represented  in  five  degrees  of  strength.  1st.  A  calm,  by  a  hori- 
zontal line  and  zero— thus  0  ;  2d.  A  light  wind,  by  an  arrow  with  one  barb  and  no 


THE    BAROMETER   AND   THE   WEATHER. 


195 


WEATHER  CHART,  OCTOBER  6,  1875. 


feathers ^ ;  3d.  Afresh  to  strong  breeze,  by  an  arrow  with  two  barbs  and  no 

feathers ^ ;  4th.  A  gals,  by  an  arrow  with  two  feathers  >         >  ;  and  5th.  A 

violent  gale,  by  an  arrow  with  four  feathers»  >.  The  temperature — in  the 
shade— is  marked  in  figures  with  a  sranll  circle  to  the  right,  indicating  degrees— as 
60-.  These  figures  ^tand  in  the  places  where  the  observations  are  made.  The 
other  figures— usually  \vi*h  decimals,  and  placed  at  the  end  of  the  dotted  lines — 
give  the  height  of  the  barometer— the  doited  line  showing  where  this  particular 
height  remained  the  same  at  the  time  of  observation.  Theee  dotted  lines  are  call- 
ed •  isobars, '  or  equal  weights— the  weight  or  over-head  pressure  of  the  atmosphere 
being  the  same  all  along  the  line. 


196  SCIENCE   IK   SHORT   CHAPTERS. 

to  find  their  level,  and  thereby  the  winds  are  produced.  The 
air  flows  from  all  sides  toward  the  lowest  isobar.  But  what, 
then,  must  be  the  course  of  the  wind  ?  Will  it  be  in  straight 
lines  toward  this  point  ?  If  so,  a  strange  conflict  must  result 
when  all  these  currents  meet  from  opposite  directions.  What 
will  follow  from  this  conflict  ?  A  skilful  physicist  can  work 
out  this  problem  mathematically,  but  we  are  not  all  rnathe- 
hnaticians,  some  of  us  are  not  able  to  follow  his  formula),  and, 
'therefore,  will  do  better  by  resorting  to  simple  observation  of 
other  analogous  and  familiar  phenomena.  A  funnel  or  any 
vessel  with  a  hole  in  the  bottom  will  answer  our  purpose.  Let 
us  fill  such  a  vessel  with  water,  then  open  the  hole  and  see 
what  will  be  the  course  of  the  water  when  it  is  struggling  to 
flow  from  all  sides  to  the  one  point  of  vacuity.  It  will  very 
soon  establish  a  vortex  or  whirlpool — i.e.  the  water  instead  of 
flowing  directly  by  straight  lines  from  the  sides  to  the  centre 
of  the  funnel,  will  take  a  roundabout,  spiral  course,  and  thus 
screw  its  way  down  the  outlet  of  the  funnel. 

This  is  just  what  occurs  when  the  air  is  rushing  to  fill  a  com- 
paratively vacuous  atmospheric  space.  It  moves  in  a  spiral  ; 
and  in  the  Northern  Hemisphere  this  spiral  always  turns  in  the 
•  same  way — viz.  in  the  opposite  direction  to  the  hands  of  a 
clock  when  flowing  inward,  and  vice  versa,  or  with  the  clock 
hands,  when  the  air  is  overflowing  from  a  centre  of  high 
pressure. 

In  the  chart  for  October  5th  both  these  cases  are  illustrated. 
North  of  Dublin  there  is  a  curvature  of  isobars  and  an  inrush 
of  winds  toward  a  northward  low  pressure,  or  vacuous  region  ; 
while  south  of  Dublin  the  isobar  tends  sharply  round  a  high- 
pressure  focus,  and  the  overflowing  wind  is  correspondingly 
reversed  in  direction,  as  shown  by  the  arrows. 

The  next  chart,  for  October  6th,  shows  that  the  overflow  has 
spread  northward  as  far  as  Dublin,  and  the  high-pressure  focus 
lias  also  moved  northward.  It  follows  from  this  that  if  you 
know  the  barometric  gradient,  and  stand  with  your  left  hand 
to  the  region  of  low  barometer  and  your  right  hand  to  that 
of  the  high  barometer,  the  wind  will  blow  against  your  back 
— i.e.  you  will  face  the  direction  of  the  wind,  or  of  those 
flying  arrows  on  the  chart.  This  interesting  and  important 
generalization  is  called  "  Buys  Ballot's  Law."  In  spite  of  the 
proverbial  fickleness  of  the  winds  this  simple  law  is  rarely 
infringed,  though  it  may  require  a  slight  modification  of 
statement — inasmuch  as  the  wind  does  not  move  in  circles  round 


THE  BAROMETER  AND  THE  WEATHER.        19? 

the  vacuous  space,  but  in  spirals,  and  thus  it  blows  not  quite 
square  to  the  back,  but  rather  obliquely,  or  a  little  on  the 
right  side.  This  is  shown  by  the  arrows  in  the  charts,  and  is 
most  strikingly  displayed  in  the  chart  for  October  6th, 
between  the  isobars  of  30 '3  and  30 '5.  To  take,  in  Ireland, 
the  position  required  by  Buys  Ballot's  Law,  one  must  have 
stood  facing  the  east,  and  accordingly,  the  westerly  wind 
would  then  blow  upon  one's  back.  In  Paris,  at  the  same 
moment,  the  position  would  be  facing  south-east,  and  the  wind 
was  curving  round  accordingly.  Further  south — at  Bordeaux 
or  the  Pyrenees — the  position  becomes  almost  reversed — i.e. 
facing  south-west,  and  the  wind  is  reversed  in  equal  degree. 

Here,  then,  on  these  days  we  had  the  chief  conditions  of 
wind  and  rain,  a  steep  and  increasing  barometric  gradient  and  a 
flow  over  our  islands  of  humid  air  from  the  south  and  west 
regions  of  the  great  Atlantic.  Strong  winds  and  heavy  rains 
did  follow  accordingly  ;  and  the  prophetic  warnings  of  the 
Meteorological  Office,  which  are  conveyed  by  means  of  signals 
displayed  on  prominent  parts  of  the  coast,  were  fulfilled. 

Mr.  Scott,  the  Director  of  the  Meteorological  Office,  tells  us 
that  "  The  degree  of  success  that  has  attended  our  warnings  in 
these  islands,  on  the  average  of  the  last  two  years,  has  been 
that  over  45  per  cent,  have  been  followed  by  severe  gales  ;  and 
over  33  per  cent,  in  addition  have  been  followed  by  wind  too 
strong  for  fishing-boats  and  yachts,  though  in  themselves  not 
severe  gales;  this  gives  a  total  percentage  of  success  of  nearly  80." 

In  winter  the  movements  of  the  air  are  more  decided,  and 
the  changes  are  often  so  rapid  that  the  warning  sometimes 
comes  too  late.  With  increased  means — i.e.  more  money  to 
cover  additional  work,  and  more  stations — better  results  might 
be  obtained.  The  United  States  expend  £50,000  a  yeai^in 
weather  telegraphy,  exclusive  of  salaries,  while  the  United 
Kingdom  only  devotes  £3000  a  year  to  the  same  purpose. 
The  difficulties  on  our  side  of  the  Atlantic  are  greater  than  on 
the  American  coasts,  on  account  of  the  greater  changeableness 
of  our  weather — mainly  due  to  the  more  irregular  distribution 
of  land  and  water  on  this  side.  This,  however,  instead  of  dis- 
couraging national  effort,  should  be  regarded  as  a  reason  for 
increasing  it.  The  greater  the  changes,  the  greater  is  the 
need  for  warnings,  and  the  greater  the  difficulty,  the  greater 
should  be  the  effort.  With  our  multitude  of  coastguard 
stations  and  naval  men  without  employment,  we  ought  to  sur- 
pass all  the  world  in  such  a  work  as  this. 


198 


SCIENCE   IK   SHORT   CHAPTERS. 


Those  among  our  readers  who  are  sufficiently  interested  in 
this  subject  to  devote  a  little  time  to  it,  may  make  a  very  in- 
teresting weather  scrap-book  by  cutting  out  the  newspaper 
chart  for  each  day,  pasting  it  in  a  suitable  album,  and  append- 
ing their  own  remarks  on  the  weather  at  the  date  of  publication 
— i.e.,  the  day  after  the  chart  observations  are  made.  Such  an 
album  would  be  far  more  interesting  than  the  postage  stamp 
and  monogram  albums  that  are  so  abundant. 

Parents  who  desire  their  children  to  acquire  habits  of  sys- 
tematic observation,  and  to  cultivate  an  intelligent  interest  in 
natural  phenomena,  will  do  well  to  supply  such  albums  to  their 
sons  or  daughters,  and  to  hand  over  to  them  the  daily  paper 
for  this  purpose. 

The  Meteorological  Office  supplies  by  post  copies  of  Daily 
Weather  Reports  to  any  subscriber  who  pays  five  shillings  per 
quarter  in  advance  ;  such  subscriptions  payable  to  Robert  H. 
Scott,  Esq.,  Director  Meteorological  Office,  116  Victoria 
Street,  Westminster,  S.W. 

These  daily  reports  are  printed  on  a  large  double  sheet,  on 
one  half  of  which  are  four  charts,  representing  separately  the 
four  records  which  are  included  in  the  one  smaller  newspaper 
chart — viz.  those  of  the  barometer,  the  thermometer,  the  rain- 
gauge,  and  the  anemometer.  On  the  other  half  of  the  sheet  is 
a  detailed  separate  tabular  statement  of  the  results  of  observa- 
tions made  at  the  following  stations  : 


Haparanda 

HernOsand 

Stockholm 

Wisby 

Christiansund 

Skudesnaes 


Wick 

Nairn 

Aberdeen 

Leith 

Shields 

York 


OxO  (Christiansund)  Scarborough 
Skagen  (The  Skaw)   Nottingham 


Fano 
Cuxhaven 
Snmburgh  Head 
Stornoway 
Thurso 


Ardrosi-an 

Greencastle 

Donaghadee 

Kingstown 

Holyhead 


Liverpool 

The  Holder 

Valencia 

Cape  Griznez 

Roche's  Point 

Brest 

Pembroke 

L1  Orient 

Portishead 

Rochefort 

Scilly 

Biarritz 

Plymouth 

Corunna 

Hurst  Castle 

Brussels 

Dover 

Charleville 

London 

Paris 

Oxford 

Lyons 

Cambridge 

Toulon 

Yarmouth 

On  Winds  and  Currents,  from  the  Admiralty  Physical  Atlas. 

In  the  Northern  Hemisphere  the  effect  of  the  veering  of  the 
wind  on  the  barometer  is  according  to  the  following  law  : 

With  east,  south-east,  and  south  winds,  the  barometer  falls. 

"With  south-west  winds,  the  barometer  ceases  to  fall  and  be- 
gins to  rise. 

With  west,  north-west,  and  north  winds,  the  barometer  rises. 


THE    CHEMISTRY   OF   BOG    RECLAMATION".  199 

With  north-east  winds,  the  barometer  ceases  to  rise  and  be- 
gins to  fall. 

In  the  Northern  Hemisphere  the  thermometer  rises  with 
east,  south-east,  and  south  winds  ;  with  a  south-west  wind  it 
ceases  to  rise  and  begins  to  fall  ;  it  falls  with  west,  north-west, 
and  north  winds  ;  and  with  a  north-east  wind  it  ceases  to  fall 
and  begins  to  rise. 


CHAPTER  XXV. 

THE    CHEMISTRY    OF    BOG    RECLAMATION 

THE  mode  of  proceeding  for  the  reclamation  of  bog-land  at 
Kylemore  is  first  to  remove  the  excess  of  water  by  **  the  big 
drain  and  the  secondary  drains,"  which  must  be  cut  deep 
enough  to  go  right  down  to  the  gravel  below.  These  are  sup- 
plemented by  the  "  sheep-drains,"  or  surface-drains,  which 
are  about  twenty  inches  wide  at  top,  and  narrow  downward  to 
six  inches  at  bottom.  They  run  parallel  to  each  other,  with  a 
space  of  about  ten  yards  between,  and  cost  one  penny  per  six 
yards. 

This  first  step  having  been  made,  the  bog  is  left  for  two 
years,  during  which  it  drains,  consolidates,  and  sinks  some- 
what. If  the  bog  is  deep,  the  turf,  which  has  now  become 
valuable  by  consolidation,  should  be  cut. 

After  this  it  is  left  about  two  years  longer,  with  the  drains 
still  open.  Then  the  drains  are  cleared  and  deepened,  and  a 
wedge-shaped  sod,  too  wide  to  reach  the  bottom,  is  rammed  in 
so  as  to  leave  below  it  a  permanent  tubular  covered  drain, 
which  is  thus  made  without  the  aid  of  any  tiles  or  other  outside 
material.  The  drainage  is  now  completed,  and  the  surface 
prepared  for  the  important  operation  of  dressing  with  lime, 
which,  as  the  people  expressively  say,  "  boils  the  bog,"  and 
converts  it  into  a  soil  suitable  for  direct  agricultural  operations. 

Potatoes  and  turnips  may  now  be  set  in  **  lazy  bed  "  ridges. 
Mr.  Mitchell  Henry  says,  **  Good  herbage  will  grow  on  the  bog 
thus  treated  ;  but  as  much  as  possible  should  at  once  be  put 
into  root-crops,  with  farm-yard  manure  for  potatoes  and  tur- 
nips. The  more  lime  you  give  the  better  will  be  your  crop  ; 
and  treated  thus  there  is  no  doubt  that  even  during  the  first 


200  SCIENCE   IN   SHORT   CHAPTERS. 

year  land  so  reclaimed  will  yield  remunerative  crops."  And 
further,  that  "  after  being  broken  up  a  second  time  the  land 
materially  improves,  and  becomes  doubly  valuable."  Also 
that  he  has  no  doubt  that  "  all  bog-lands  may  be  thus  re- 
claimed, but  it  is  up-hill  work,  and  not  remunerative  to  attempt 
the  reclamation  of  bogs  that  are  more  than  four  feet  in  depth." 

There  is  another  and  a  simpler  method  of  dealing  with  bogs 
— viz.  setting  it  into  narrow  ridges  ;  cutting  broad  trenches 
between  the  ridges  ;  piling  the  turf  cut  out  from  these  trenches 
into  little  heaps  a  few  feet  apart,  burning  them,  and  spreading 
•  the  ashes  over  the  ridges.  This  is  rather  largely  practised  on 
the  coast  of  Donegal,  in  conjunction  with  sea-weed  manuring, 
and  is  prohibited  in  other  parts  of  Ireland  as  prejudicial  to  the 
interests  of  the  landlord. 

We  shall  now  proceed  to  the  philosophy  of  these  processes. 

First,  the  drainage.  Everybody  in  Ireland  knows  that  the 
bog  holds  water  like  a  sponge,  and  in  such  quantities  that  ordi- 
nary vegetation  is  rotted  by  the  excess  of  moisture.  There  is 
good  reason  to  believe  that  the  ancient  forests,  which  once  oc- 
cupied the  sites  of  most  of  the, Irish  bogs,  were  in  some  cases 
destroyed  by  the  rotting  of  their  stems  and  roots  in  the  excess 
of  vegetable  soil  formed  by  generations  upon  generations  of 
fallen  leaves,  which,  in  a  humid  climate  like  that  of  Ireland, 
could  never  become  drained  or  air-dried. 

But  this  is  not  all.  There  is  rotting  and  rotting.  When  the 
rotting  of  vegetable  matter  goes  on  under  certain  conditions  it 
is  highly  favorable  to  the  growth  of  other  vegetation,  even  of 
the  vegetation  of  the  same  kind  of  plants  as  those  supplying 
the  rotting  material.  Thus  rotten  and  rotting  straw  is  a  good 
manure  for  wheat  ;  and  the  modern  scientific  vine-grower  care- 
fully places  the  dressing  of  his  vines  about  their  roots,  in  order 
that  they  may  rot,  and  supply  the  necessary  salts  for  future 
growth.  The  same  applies  generally  ;  rotting  cabbage  leaves 
supply  the  best  of  manure  for  cabbages  ;  rotting  rhubarb  leaves 
for  rhubarb  ;  rose  leaves  for  rose  trees  ;  and  so  on  throughout 
the  vegetable  kingdom. 

Why,  then,  should  the  bog  -  rotting  be  so  exceptionally 
malignant  ?  As  I  am  not  aware  that  any  answer  has  been  given 
to  this  question,  I  will  venture  upon  one  of  my  own.  It  ap- 
pears to  be  mainly  due  to  the  excess  of  moisture  preventing 
that  slow  combustion  of  vegetable  carbon  which  occurs  wher- 
ever vegetable  matter  is  heaped  together  and  slightly  moist- 
ened. We  see  this  going  on  in  steaming  dunghills  ;  in  hay- 


THE    CHEMISTRY    OF    BOG    RECLAMATION.  201 

ricks  that  have  been  stacked  when  imperfectly  dried  ;  in  the 
spontaneous  combustion  of  damp  cotton  in  the  holds  of  ships, 
and  in  factories  where  cotton-waste  has  been  carelessly  heaped  ; 
and  in  cucumber-frames  and  the  other  "  hot-beds"  ot  the 
gardener. 

In  ordinary  soils  this  combustion  goes  on  more  slowly,  but 
no  less  effectively,  than  in  these  cases.  In  doing  so  it  main- 
tains a  certain  degree  of  warmth  about  the  roots  of  the  plants 
that  grow  there,  and  gradually  sets  free  the  soluble  salts  which 
the  rotting  vegetables  contain,  and  supplies  them  to  the  grow- 
ing plants  as  manure,  at  the  same  time  forming  the  humus  so 
essential  to  vegetation. 

A  great  excess  of  water,  such  as  soddens  the  bog,  prevents 
this,  and  also  carries  away  any  small  quantity  of  soluble  nutri- 
tious salts  the  soil  may  contain.  Thus  instead  of  being  warmed 
and  nourished  by  slight  humidity,  and  consequent  oxidation, 
the  bog  soil  is  chilled  and  starved  by  excess  of  water. 

The  absolute  necessity  of  the  first  operation — that  of  drain- 
age— is  thus  rendered  obvious  ;-  and  I  suspect  that  the  need  of 
four  years'  rest,  upon  which  Mr.  MacAlister  insists,  is  somehow 
connected  with  a  certain  degree  of  slow  combustion  that  accom- 
panies and  partially  causes  the  consolidation  of  the  bog.  I 
have  not  yet  had  an  opportunity  of  testing  this  by  inserting 
thermometers  in  bogs  under  different  conditions,  but  hope  to 
do  so. 

The  liming  next  demands  explanation.  Mr.  Henry  says  that 
"  it  leaves  the  soil  sweetened  bv  the  neutralization  of  its 
acids." 

In  order  to  test  this  theory  I  have  digested  (i.e.  soaked)  vari- 
ous samples  of  turf  cut  from  Irish  bogs  in  distilled  water, 
filtered  off  the  water,  and  examined  it.  I  find  that  when  this 
soaking  has  gone  far  enough  to  give  the  water  a  coloring,  simi- 
lar to  that  which  stands  in  ordinary  bogs,  the  acidity  is  very 
decided — quite  sufficiently  so  to  justify  this  neutralization  the- 
ory as  a  partial  explanation.  There  is  little  reason  to  doubt 
that  the  lime  is  further  effective  in  enriching  the  soil  ;  or,  in 
the  case  of  pure  bogs,  that  it  forms  the  soil  by  disintegrating 
and  decomposing  the  fibrous  vegetable  matter,  and  thus  render- 
ing it  capable  of  assimilation  by  the  crops. 

Another  effect  which  the  lime  must  produce  is  the  liberation 
of  free  ammonia  from  any  fixed  salts  that  may  exist  in  the  bog. 

The  bog-burning  method  of  reclamation  is  easily  explained. 
In  the  first  place,  the  excessive  vegetable  incurnbrance  is 


202  SCIENCE   IK   SHORT   CHAPTERS. 

* 

reduced  in  quantity,  and  the  remaining  ashes  supply  the  surface 
of  the  bog  on  which  they  rest  with  the  non-volatile  salts  that 
originally  existed  in  the  burned  portions  of  the  bog.  In  other 
words,  they  concentrate  in  a  small  space  the  salts  that  were 
formerly  distributed  too  sparsely  through  the  whole  of  the  turf 
which  was  binned. 

As  there  are  great  differences  in  the  composition  of  different 
bogs,  especially  in  this  matter  of  mineral  ash,  it  is  evident  that 
the  success  of  this  method  must  be  very  variable,  according  to 
the  locality. 

On  discussing  this  method  with  Mr.  MacAlister  (Mr.  Henry's 
steward,  under  whose  superintendence  these  reclamation  works 
are  carried  out),  he  informed  me  that  the  bogs  on  the  Kylemore 
estate  yield  a  very  small  amount  of  ash — a  mere  impalpable 
powder  that  a  light  breath  might  blow  away  ;  that  it  was  prac- 
tically valueless,  excepting  from  the  turf  taken  at  nearly  the 
base  of  the  bog.  The  ash  I  examined  where  the  bog  burning 
is  extensively  practised  in  Donegal  Avas  quite  different  from 
this.  The  quantity  was  far  greater,  and  its  substance  more 
granular  and  gritty.  It,  in  fact,  formed  an  important  stratum 
when  spread  over  the  surface  of  the  ridges.  These  differences 
of  composition  may  account  for  the  differences  of  opinion  and 
practice  which  prevail  in  different  districts.  It  affords  a  far 
more  rational  explanation  than  the  assumption  that  all  such 
contradictions  arise  from  local  stupidities. 

There  is  one  evil,  however,  which  is  common  to  all  bog- 
burning  as  compared  with  liming — it  must  waste  the  ammonia- 
cal  salts,  as  they  are  volatile,  and  are  driven  away  into  the  air 
by  the  heat  of  combustion.  Somebody  may  get  them  when 
the  rain  washes  them  down  to  the  earth's  surface  again  ;  but 
the  burner  himself  obtains  a  very  small  share  in  this  way. 

We  may  therefore  conclude  that  where  lime  is  near  at  hand, 
bog-burning  is  a  rude  and  wasteful,  a  viciously  indolent  mode 
of  reclamation.  It  is  only  desirable  where  limestone  is  so  dis- 
tant that  the  expense  of  carriage  renders  lime  practically  un- 
attainable, and  where  the  bog  itself  is  rich  in  mineral  matter, 
and  so  deep  and  distant  from  a  fuel  demand  that  it  may  be 
burned  to  waste  without  any  practical  sacrifice.  Under  such 
conditions  it  may  be  better  to  burn  the  bog  than  leave  it  in 
hopeless  and  worthless  desolation. 

I  cannot  conclude  without  again  adverting  to  the  importance 
of  this  subject,  and  affirming  with  the  utmost  emphasis,  that 
1he  true  Irish  patriot  is  not  the  political  orator,  but  he  who  by 


THE   CHEMISTRY  OF   BOG   RECLAMATION.  203 

practical  efforts,  either  as  capitalist,  laborer,  or  teacher,  pro- 
motes the  reclamation  of  the  soil  of  Ireland,  or  otherwise  de- 
velops the  sadly  neglected  natural  resources  of  the  country. 

With  Mr.  Mitchell  Henry's  permission  I  append  to  the 
above  his  own  description  of  the  results  of  his  experiment, 
originally  communicated  in  a  letter  to  the  Times  ;  at  the  same 
time  thanking  him  for  his  kind  reception  of  a  stranger  at  Kyle- 
more  Castle,  and  the  facilities  he  afforded  me  for  studying  the 
subject  on  the  spot. 

"  The  interesting  account  you  lately  published  of  the  exten- 
sive reclamations  of  His  Grace  the  Duke  of  Sutherland,  under 
the  title  of  *  An  Agricultural  Experiment,'  has  been  copied  into 
very  many  newspapers,  and  must  have  afforded  a  welcome  re- 
lief to  thousands  of  readers  glad  to  turn  for  a  time  from  the 
terrible  narratives  that  come  to  us  from  the  east.  If  you  will 
allow  me,  I  should  like  to  supplement  your  narrative  by  a  rapid 
sketch  of  what  has  been  done  here  during  the  last  few  years, 
on  a  much  humbler  scale,  in  the  case  of  land  similar,  and  some 
of  it  almost  identical,  with  that  in  Sutherlandshire. 

11  The  twelve  corps  d'armee  under  the  duke's  command,  in 
the  shape  of  the  twelve  steam-engines  and  their  ploughs, 
engaged  in  subduing  the  stubborn  resistance  of  the  unreclaimed 
wilds  of  Sutherlandshire,  suggest  to  the  mind  the  triumphs  of 
great  warriors,  and  fill  us  with  admiration — not  always  excited 
by  the  details  of  great  battles  ;  but,  as  great  battles  can  be 
fought  seldom,  and  only  by  gigantic  armies  and  at  prodigious 
expense,  so  reclamation  on  such  a  scale  is  far  beyond  the  op- 
portunities or  the  means  of  most  of  us  ;  while  many  may,  per- 
haps, be  encouraged  to  attempt  work  similar  to  that  which  has 
been  successfully  carried  out  here. 

"  And,  first  of  all,  a  word  as  to  the  all-important  matter  of 
cost.  Does  it  pay  ? 

"  Including  farm-buildings  and  roads,  the  reclamations  here 
have  cost  on  an  average  £13  an  acre,  which,  at  5  per  cent., 
means  an  annual  rent-charge  of  13s.,  to  which  is  to  be  added  a 
sum  of  from  Is.  to  36'.,  the  full  annual  value  of  the  unreclaimed 
land.  It  is  obvious  that  if  we  start  with  an  outlay  of  £30  plus 
the  Is.  to  3s.  of  original  rent,  such  an  amount  would  usually  be 
found  prohibitory  ;  but,  on  the  other  hand,  excellent  profits 
may  be  made  if  the  expenditure  is  so  kept  down  that  the  an- 
nual rent  is  not  more  than  from  15s.  to  18s.  per  acre.  Before 
entering  into  further  details,  let  me  say  that  I  claim  no  credit 
for  originality  in  what  has  been  done.  The  like  has  been 


204  SCIENCE   IN   SHORT   CHAPTERS. 

effected  on  numerous  properties  in  Ireland  in  bygone  days,  anfr 
is  daily  being  carried  out  by  the  patient  husbandman  who  yea* 
by  year  with  his  spade  reclaims  a  little  bit  from  the  mountain^ 
side.  And  you  must  allow  me  emphatically  to  say  that  what 
has  been  done  here  economically  and  well  would  not  have  been 
done  except  for  the  prudence,  patience,  and  thoughtful  mind 
of  my  steward,  Archibald  MacAlister,  a  county  Antrim  man, 
descended  from  one  of  the  race  of  Highland  Catholic  Scotch 
settlers  who  have  peopled  the  North  of  Ireland  and  added  so 
much  to  its  prosperity. 

"  The  Pass  of  Kylcmore,  in  which  I  live,  is  undoubtedly 
favorably  situated  for  reclamation,  for  there  is  but  little  very 
deep  bog,  and  there  is  abundance  of  limestone.  In  former 
ages  it  must  have  been  an  estuary  of  the  sea,  with  a  river  flow- 
ing through  it,  now  represented  by  a  chain  of  lakes  and  the 
small  rapid  river  Dowris.  The  subsoil  is  sand,  gravel,  and 
schist  rock,  with  peat  of  various  depths  grown  upon  it.  As 
by  the  elevation  of  the  land  the  sea  long  ages  ago  was  driven 
back,  the  mossy  growth  of  peat  commenced,  followed  by  pine 
and  yew  trees,  of  which  the  trunks  and  roots  are  abundantly 
found  ;  but,  except  over  a  space  of  about  400  acres,  every  tree 
that  formerly  clothed  the  hill-sides  has  been  cut  down  or  has 
totally  disappeared.  The  general  result  is  that  we  have  a  pass 
several  miles  long,  bounded  on  the  north  and  the  south  by  a 
chain  of  rugged  mountains  of  some  1500  or  1800  feet  in 
height,  while  the  east  is  blocked  up  by  a  picturesque  chain  run- 
ning north  and  south,  and  separating  the  Joyce  country  from 
Connemara  proper,  the  west  being  open  to  the  Atlantic.  The 
well-known  Killery  Bay,  or  Fiord^  would,  I  doubt  not,  present 
an  exact  resemblance  to  Kylemore  if  the  sea,  which  now  flows 
up  to  its  head,  were  driven  out.  There  are  miles  of  similar 
country  in  Ireland,  waiting  only  for  the  industry  of  man, 
where,  as  here,  there  exist  extensive  stretches  of  undulating 
eskers,  covered  with  heather  growing  on  the  light  clay,  with  a 
basis  of  gravel  or  sand. 

"  A  considerable  difference  exists  between  the  reclamation 
of  the  flat  parts,  where  the  bog  is  pretty  deep,  and  the  hill- 
sides, where  there  is  little  or  no  bog.  Yet  it  is  to  be  remem- 
bered that  bog  is  nothing  more  than  vegetable  matter  in  a  state 
of  partial  decomposition,  and  holding  water  like  a  sponge. 
The  first  thing  is  to  remove  the  water  by  drains,  some  of  which 
— that  is,  the  big  drain  and  the  secondary  drains — must  go 
right  down  to  the  gravel  below  ;  but  the  other  drains — called 


THE   CHEMISTRY    OF   BOG   RECLAMATION.  205 

sheep-drains — need  not,  and,  indeed,  must  not  be  cut  so  deep. 
The  drains  are  cut  wedge-shape  by  what  are  called  Scotch 
tools,  which  employ  three  men — two  to  cut  and  one  to  hook 
out  the  sods  ;  and  all  that  is  requisite  to  form  a  permanent 
drain  is  to  replace  the  wedge-shaped  sod,  and  ram  it  down  be*- 
tween  the  walls  of  the  drain,  where  it  consolidates  and  forms  a 
tube  which  will  remain  open  for  an  indefinite  number  of  years. 
We  have  them  here  as  good  as  new,  made  twenty-five  years 
ago  ;  and  at  Chat  Moss,  in  Lancashire,  they  are  much  older. 
After  land  has  been  thus  drained — but  not  too  much  drained, 
or  it  will  become  dry  turf — the  surface  begins  to  sink  ;  what 
was  tumid  settles  down,  and  in  the  course  of  a  few  months  the 
land  itself  becomes  depressed  on  the  surface  and  much  consoli- 
dated. Next  it  is  to  be  dug  by  spade- labor  or  ploughed.  We 
use  oxen  largely  for  this  purpose,  and,  strange  to  say,  the  best 
workers  we  find  to  be  a  cross  with  the  Alderney,  the  result 
being  a  light,  wiry  little  animal,  which  goes  gayly  over  the 
ground,  is  easy  to  feed,  and  very  tractable.  The  oxen  are 
trained  by  the  old  wooden  neck-yoke  ;  but,  when  well  broken, 
work  in  collars,  which  seem  more  easy  to  them.  Horses  on 
very  soft  land  work  well  in  wooden  pattens.  After  the  land 
has  been  broken  up,  a  good  dressing  of  lime  is  to  be  applied  to 
it,  and  this,  in  the  expressive  language  of  the  people  here, 
"  boils  the  bog" — that  is,  the  lime  causes  the  vegetable  matter, 
formerly  half  decomposed,  to  become  converted  into  excellent 
manure.  This  leaves  the  soil  sweetened  by  the  neutralization 
of  its  acids,  and  in  a  condition  pretty  easily  broken  up  by  the 
chain-harrow  ;  or,  what  is  better  still,  by  Randall's  American 
revolving  harrow. 

"  Good  herbage  will  grow  on  bog  thus  treated,  but  as  much 
as  possible  should  at  once  be  put  into  root-crops,  with  farm- 
yard manure  for  potatoes  and  turnips.  The  more  lime  you 
give  the  better  will  be  your  crop,  and  treated  thus,  there  is  no 
doubt  that  even  during  the  first  year  land  so  reclaimed  will 
yield  remunerative  crops.  People  ask,  "  But  will  not  the 
whole  thing  go  back  to  bog  ?"  Of  course  it  will  if  not  kept 
under  proper  rotation,  which  we  find  to  be  one  of  five  years — 
namely,  roots  followed  by  oats,  laid  down  with  clover  and 
grass  seed,  which  remain  for  two  years.  After  being  broken  up 
a  second  time,  the  land  materially  improves  and  becomes  doubly 
valuable.  I  have  no  doubt  that  all  bog-lands  may  be  thus  re- 
claimed, but  it  is  up-hill  work  and  not  remunerative  to  attempt 
the  reclamation  of  bogs  that  are  more  than  four  feet  in  depth. 


206  SCIENCE   IN"   SHORT   CHAPTERS. 

"  And  here  I  will  make  a  remark  as  to  the  effects  of  drain- 
age in  a  wet  country.  By  no  means  does  the  whole  effect 
result  from  raising  the  temperature  of  the  soil  ;  there  is  some- 
thing else  as  important,  and  that  is  the  supply  of  ammonia, 
brought  down  from  the  skies  in  the  rain,  which,  with  other 
fertilizing  matter,  is  caught,  detained,  and  absorbed  in  the  soil. 
A  well-drained  field  becomes,  in  fact,  just  like  a  water-meadow 
I  over  which  a  river  flows  for  a  part  of  a  year  ;  and  thus  the  very 
wetness  of  the  climate  may  be  made  to  reduce  the  supply  of 
amrnoniacal  manures,  so  expensive  to  buy. 

**  The  porous,  well-drained  soil  carries  quickly  off  the  super- 
fluous moisture,  while  the  ammonia  is  absorbed  by  the  roots 
and  leaves  of  the  plants.  An  excessive  bill  for  amrnoniacal 
manures  has  been  the  ruin  of  many  a  farmer  ;  and  our  aim  in 
Ireland  should  be  to  secure  good  crops  by  thorough  drainage 
and  constant  stirring  of  the  soil,  without  much  outlay  for  con- 
centrated manures.  At  the  same  time,  I  ought  to  remark  that 
we  have  grown  excellent  potatoes  by  using  £5  worth  per  acre 
of  superphosphate  and  nitrate  of  soda  in  cases  in  which  our 
farmyard  manure  has  fallen  short. 

"  The  reclamation  of  mountain-land  as  distinguished  from 
bog-land  can  best  be  illustrated  by  a  record  of  what  has  been 
accomplished  on  two  farms  here.  Three  years  ago  the  leases 
of  two  upland  farms  fell  in,  and  I  took  them  into  my  own 
hands.  The  flrst  consists  of  600  acres,  one  half  a  nearly  level  flat 
of  decpish  bog  running  alongside  the  river,  the  other  half  moor 
heath,  which  with  difficulty  supported  a  few  sheep  and  cattle. 

"  There  had  never  been  any  buildings  on  this  land,  nor  had 
a  spade  ever  been  put  into  it  ;  and  the  tenant,  being  unable  to 
pay  his  rent  of  £15  a  year  for  the  600  acres,  was  glad  to 
give  it  up  for  a  moderate  consideration.  The  first  thing  ac- 
complished was  to  fence  and  drain  thoroughly  as  before  de- 
scribed, and  the  best  half  of  the  land  was  then  divided  into 
forty-acre  fields.  Exactly  now  two  years  ago — on  September 
loth — a  little  cottage  and  a  stable  for  a  pair  of  horses  and  a 
pair  of  bullocks  was  completed  and  tenanted  by  two  men  and  a 
boy.  They  ploughed  all  the  week  and  came  home  on  Satur- 
days to  draw  their  supply  of  food  and  fodder  for  the  ensuing 
seven  days,  thus  approximating  very  nearly  to  the  position  of 
settlers  in  a  new  country.  We  limed  all  the  land  we  could, 
manured  part  of  it  with  seaweed  and  part  with  the  farm- 
manure  made  by  the  horses  and  oxen  which  were  at  work,  and 
cropped  with  roots  such  as  turnips  and  potatoes.  A  good  por- 


THE   CHEMISTRY   OF    BOG    RECLAMATION.  207 

tion  we  sowed  with  oats  out  of  the  lea,  but  the  most  satisfac- 
tory crop  \ve  found  to  be  rape  and  grasses  mixed,  for  on  the 
best  of  the  land  they  form  at  once  an  excellent  permanent  past- 
ure. We  have  now  had  two  crops  from  this  land  ;  and  I 
venture  to  say  that  the  thirteen  stacks  of  oats  and  hay  gathered 
in  in  good  condition,  and  the  turnips  and  roots  now  growing, 
which  are  not  excelled  in  the  county  Galway — except  those  of 
Lord  Clancarty  at  Ballinasloe,  who  has  grown  110  tons  of  tur- 
nips to  the  Irish  acre,  equal  to  upward  of  68  tons  to  the  acre  here 
— present  a  picture  most  gratifying  and  cheering  in  every  way. 

"  The  second  farm  of  240  acres,  which  adjoins  this,  had  a 
good  building  on  it ;  but,  having  been  let  on  lease  at  about 
10s.  an  acre  to  a  large  grazier  whose  stock-in-trade  was  a 
horse,  a  saddle,  and  a  pair  of  shears,  had  not  been  cultirated 
or  improved. 

*'  Similar  proceedings  on  this  farm  have  produced  similar  re- 
sults ;  and,  if  now  let  in  the  market,  I  have  no  doubt  that  after 
two  years  of  good  treatment  these  farms  would  be  let  at  205.  an 
acre,  and  I  do  not  despair  of  doubling  this  figure  in  the  course 
of  time. 

"  The  exact  weight  of  the  turnip  crop  this  season  is,  on  raw 
bog,  drained,  limed,  and  cropped  this  year  for  the  first  time, 
24  tons  per  acre  ;  manure,  seaweed.  On  land  ploughed  but 
not  cropped,  last  year  23-£  tons  ;  mixed  mineral  manure.  On 
and  from  which  a  crop  of  oats  had  previously  been  taken,  29 
tons  ;  manure,  farmyard,  with  3  cwt.  per  acre  mineral  manure. 

"  Last  year  my  excellent  steward,  Mr.  MacAlister,  visited 
the  Duke  of  Sutherland's  reclamations  in  Scotland,  and  was 
kindly  and  hospitably  received.  He  found  the  land  and  the 
procedure  adopted  almost  identical,  with  the  conviction  that 
oxen  and  horses  will  suit  us  better  at  the  present  time  than 
steam  culture,  chiefly  on  the  score  of  economy.  He  also  visit- 
ed the  Bridgewater  Estate  at  Chat  Moss,  near  Manchester, 
where  so  much  has  been  done  to  bring  the  deep  peat  into  culti- 
vation, and  he  found  the  system  that  has  been  followed  there 
for  so  many  years  to  be  like  that  described  above,  marl,  how- 
ever, being  used  in  the  place  of  lime." 

At  the  time  of  my  visit  to  Kylcmorc  the  hay  crops  were 
down  and  partly  carried  on  the  reclaimed  bog-land  above  de- 
scribed. The  contrast  of  its  luxuriance  with  the  dark  and 
dreary  desolation  of  the  many  estates  1  had  seen  during  three 
summers'  wanderings  through  Ireland  added  further  proof  of 
the  infamy  of  the  majority  of  Irish  landlords,  by  showing  what 
Ireland  would  have  been  had  they  done  their  duty. 


208  SCIENCE   IN   SHOUT    CHAPTERS. 

CHAPTER    XXVI. 

AERIAL  EXPLORATION   OF   THE  ARCTIC   REGIONS. 

ON  our  own  hemisphere,  and  separated  from  our  own  coasts  by 
only  a  few  days'  journey  on  our  own  element,  there  remains  a  blank 
circle  of  unexplored  country  above  800  miles  in  diameter.  We  have 
tried  to  cross  it,  and  have  not  succeeded.  Nothing  further  need  be 
said  in  reply  to  those  who  ask,  "  Why  should  we  start  another  Arctic 
Expedition?" 

The  records  of  previous  atempts  to  penetrate  this  area  of  geo- 
graphical mystery  prove  the  existence  of  a  formidable  barrier  of 
mountainous  land,  fringed  by  fiords  or  inlets,  like  those  of  Norway, 
some  of  which  may  be  open,  though  much  contracted  northward,  like 
the  Vestf jord  that  lies  between  the  Lofoden  Islands  and  the  mainland 
of  Scandinavia.  The  majority  evidently  run  inland  like  the  ordinary 
Norwegian  fiords  or  the  Scotch  firths,  and  terminate  in  land  valleys 
that  continue  upward  to  field  regions,  or  elevated  humpy  land  which 
acts  as  a  condenser  to  the  vapor-laden  air  continually  flowing  toward 
the  Pole  from  the  warmer  regions  of  the  earth,  and  returning  in 
lower  streams  when  cooled.  The  vast  quantities  of  water  thus  con- 
densed fall  upon  these  hills  and  table  lands  as  snow  crystals.  What 
becomes  of  this  everlasting  deposit  ? 

Unlike  the  water  that  rains  on  temperate  hill-sides,  it  cannot  all 
flow  down  to  the  sea  as  torrents  and  liquid  rivers,  but  it  does  come 
down  nevertheless,  or  long  ere  this  it  would  have  reached  the  highest 
clouds.  It  descends  mainly  as  glaciers,  which  creep  down  slowly,  but 
steadily  and  irresistibly,  filling  up  the  valleys  on  their  way  ;  and 
stretching  outward  into'the  fiords  and  channels,  which  they  block  up 
with  their  cleft  and  chasmed  crystalline  angular  masses  that  still 
creep  outward  to  the  sea  until  they  float,  and  break  off  or  "calve"  as 
mountainous  icebergs  and  smaller  masses  of  ice. 

These  accumulations  of  ice  ihna  formed  on  land  constitute  the  chief 
obstructions  that  bar  the  channels  and  inlets  fringing  the  unknown 
Polar  area.  The  glacier  fragments  above  described  are  cemented  to- 
gether in  the  winter  time  by  the  freezing  of  the  water  between  them. 
An  open  frozen  sea,  pure  and  simple,  instead  of  forming  a  barrier  to 
Arctic  exploration,  would  supply  a  most  desirable  highway.  It  must 
not  be  supposed  that,  because  the  liquid  ocean  is  ruffled  by  ripples, 
waves,  and  billows,  a  frozen  sea  would  have  a  similar  surface.  The 
freezing  of  such  a  surface  could  only  start  at  the  calmest  intervals, 
and  the  ice  would  shield  the  water  from  the  action  of  the  wave-mak- 
ing wind,  and  such  a  sea  would  become  a  charming  skating  rink,  like 
the  Gulf  of  Bothnia,  the  Swedish  and  Norwegian  lakes,  and  certain 
fiords,  which,  in  the  winter  time,  become  natural  ice -paved  highways 
offering  incomparable  facilities  for  rapid  locomotion.  In  spite  of  the 
darkness  and  the  cold,  winter  is  the  travelling  season  in  Sweden  and 
Lapland.  The  distance  that  can  be  made  in  a  given  time  in  summer 
with  a  wheeled  vehicle  on  well-made  post  roads,  can  be  covered  in 
half  the  time  in  fipulk  or  reindeer  sledge  drawn  over  the  frozen  lakes. 
From  Spitzbergen  to  the  Pole  would  be  an  easy  run  of  five  or  six  days 
if  nothing  but  a  simply  frozen  sea  stood  between  them. 


AERIAL   EXPLORATION   OF   THE   ARCTIC   REGIONS.     209 

This  primary  physical  fact,  that  Arctic  navigators  have  not  been 
stopped  by  a  merely  frozen  sea,  but  by  a  combination  of  glacier  frag- 
ments with  the  frozen  water  of  bays,  and  creeks,  and  fiords,  should 
be  better  understood  than  it  is  at  present,  for  when  it  is  understood, 
the  popular  and  fallacious  notion  that  the  difficulties  of  Arctic  prog- 
ress are  merely  dependent  on  latitude,  and  must  therefore  increase 
with  latitude,  explodes. 

It  is  the  physical  configuration  of  the  fringing  zone  of  the  Arctic  regions, 
not  its  mere  latitude,  that  bars  the  way  to  the  Pole. 

I  put  this  in  italics  because  so  much  depends  upon  it — I  may  say 
that  all  depends  upon  it— for  if  this  barrier  can  be  scaled  at  any  part 
we  maj'  come  upon  a  region  as  easily  traversed  as  that  part  of  the 
Arctic  Ocean  lying  between  the  North  Cape  and  Spitzbergen,  which 
is  regularly  navigated  every  summer  by  hardy  Norsemen  in  little 
sailing  sloops  of  30  to  40  tons  burden,  and  only  six  or  eight  pair  of 
hands  on  board  ;  or  by  overland  travelling  as  easily  as  the  Arctic 
winter  journey  between  Tornea  and  Alten.  This  trip  over  the  snow- 
covered  mountains  is  done  in  five  or  six  days,  at  the  latter  end  of 
every  November,  by  streams  of  visitors  to  the  fair  at  Alten,  in  lati- 
tude 70°,  3£  degrees  N.  of  the  Arctic  circle  ;  its  distance,  430  miles,  is 
just  about  eqital  to  that  which  stands  between  the  North  Pole  and 
the  northernmost  reach  of  our  previous  Arctic  expeditions.  One  or 
the  other  of  the  above-named  conditions,  or  an  enclosed  frozen  Polar 
ocean,  is  what  probably  exists  beyond  the  broken  fiord  barrier 
hitherto  explored  ;  a  continuation  of  such  a  barrier  is,  in  fact,  almost 
a  physical  impossibility  ;  and  therefore  the  Pole  will  be  ultimately 
reached,  not  by  a  repetition  of  such  weary  struggles  as  those  which 
ended  in  the  very  hasty  retreat  of  our  last  expedition,  but  by  a  bound 
across  about  400  miles  of  open  or  frozen  Polar  ocean,  or  a  rapid 
sledge -run  over  snow-paved  fields  like  those  so  merrily  traversed  in 
Arctic  Norway  by  festive  bonders  and  their  families  on  their  way  to 
Yule-time  dancing  parties. 

Reference  to  a  map  of  the  circumpolar  regions,  or,  better,  to  a 
globe,  will  show  that  the  continents  of  Europe,  Asia,  and  America 
surround  the  Pole,  and  hang,  as  it  were,  downward  or  southward 
from  a  latitude  of  70°  and  upward.  There  is  but  one  wide  outlet  for 
the  accumulations  of  Polar  ice,  and  that  is  between  Norway(and  Green- 
land, with  Iceland  standing  nearly  midway.  Davis's  and.Behring's 
Straits  are  the  narrower  openings  ;  the  first  may  be  only  a  fiord, 
rather  than  an  outlet.  The  ice-block,  or  crowding  together  and 
heaping  up  of  the  glacier  fragments  and  bay  ice,  is  thus  explained. 

Attempts  of  two  kinds  have  been  made  to  scale  this  icy  barrier. 
Ships  have  sailed  northward,  threading  a  dangerous  course  between 
the  floating  icebergs  in  the  summer,  and  becoming  fast  bound  in 
winter,  when  the  narrow  spaces  of  brackish  water  lying  between 
these  masses  of  land  ice  become  frozen,  and  the  "  ice  foot  "  clinging 
to  the  shore  stretches  out  seaward  to  meet  that  on  the  opposite  side 
of  the  fiord  or  channel.  The  second  method,  usually  adopted  as 
supplementary  to  the  first,  is  that  of  dragging  sledges  over  these 
glacial  accumulations.  The  pitiful  rate  of  progress  thus  attainable  is 
shown  by  the  record  of  the  last  attempt,  when  Commander  Markhani 
achieved  about  one  mile  per  day,  and  the  labor  of  doing  this  was 
nearly  fatal  to  his  men.  Any  tourist  who  has  crossed  or  ascended 
an  Alpine  glacier  with  only  a  knapsack  to  carry,  can  understand  the 


210  SCIENCE   IN   SHORT    CHAPTERS. 

difficulty  of  dragging  a  cartload  of  provisions,  etc.,  over  such  accu- 
mulations of  iceberg  fragments  and  of  sea-ice  squeezed  and  crumpled 
up  between  them.  It  is  evident  that  we  must  either  find  a  natural 
breach  in  this  Arctic  barrier  or  devise  some  other  means  of  scaling  it. 

The  first  of  these  efforts  has  been  largely  discussed  by  the  advo- 
cates of  rival  routes.  I  will  not  go  into  this  question  at  present,  biit 
only  consider  the  alternative  to  all  land  routes  and  all  water  routes, 
viz.,  that  by  the  other  available  element— an  aCrial  route— as  pro- 
posed to  be  attempted  in  the  new  Arctic  expedition  projected  by 
Commander  Cheyne,  and  which  he  is  determined  to  practically  carry 
out,  provided  his  own  countrymen,  or,  failing  them,  others  more 
worthy,  will  assist  him  with  the  necessary  means  of  doing  so. 

To  reach  the  Pole  from  the  northernmost  point  already  attained  by 
our  ships  demands  a  journey  of  about  400  miles,  the  distance  be- 
tween London  and  Edinburgh.  With  a  favorable  wind,  a  balloon 
will  do  this  in  a  few  hours.  On  November  27th,  1870,  Captain  Eoher 
descended  near  Lysthuus,  in  Hitterdal  (Norway),  in  the  balloon 
"  Ville  d'Orleans,"  having  made  the  journey  from  Paris  in  fifteen 
hours.  The  distance  covered  was  about  900  miles,  more  than  double 
the  distance  between  the  Pole  a  ad  the  accessible  shores  of  Greenland. 

On  November  7th,  1836,  Messrs.  Holland,  Mason,  and  Green 
ascended  from  Vauxhall  Gardens,  at  1.30  P.M.,  with  a  moderate  breeze, 
and  descended  eighteen  hours  afterward  "  in  the  Duchy  of  Nassau, 
about  two  leagues  from  the  town  of  Weilburg, "  the  distance  in  a 
direct  line  being  about  500  miles.  A  similar  journey  to  this  would 
carry  Commander  Cheyne  from  his  ship  to  the  North  Pole,  or  there- 
about, while  a  fresh  breeze  like  that  enjoyed  by  Captain  Eoher 
would,  in  the  same  time,  carry  him  clear  across  the  whole  of  the  cir- 
cumpolar  area  to  the  neighborhood  of  Spitzbergen,  and  two  or  three 
hours  more  of  similar  proceeding  would  land  him  in  Siberia  or 
Finland,  or  even  on  the  shores  of  Arctic  Norway,  where  he  could  take 
the  Vadso  or  Hammerfest  packet  to  meet  one  of  Wilson's  liners  at 
Trondhjem  or  Bergen,  and  thus  get  from  the  North  Pole  to  London 
in  ten  days. 

Lest  any  of  my  readers  should  think  that  I  am  writing  this  at  ran- 
dom, I  will  supply  the  particulars.  I  have  before  me  the  "  Norges 
Communicationer"  for  the  present  summer  season  of  1880.  Twice 
every  week  a  passenger  excursion  steam  packet  sails  round  the  North 
Cape  each  way,  calling  at  no  less  than  twenty  stations  on  this  Arctic 
face  of  Europe  to  land  and  embark  passengers  and  goods.  By  taking 
that  which  stops  at  Gjesvaer  (an  island  near  the  foot  of  the  North 
Cape)  on  Saturday,  or  that  which  starts  from  Hammerfest  on  Sunday 
morning,  Trondhjem  is  reached  on  Thursday,  and  Wilson's  liner,  the 
Tasso,  starts  on  the  same  day  for  Hull,  "average  passage  seventy 
hours."  Thus  Hammerfest,  the  northernmost  town  in  the  world,  is 
now  but  eight  days  from  London,  including  a  day's  stop  at  Tromso, 
the  capital  of  Lapland,  which  is  about  3°  N.  of  the  Arctic  circle,  and 
within  a  week  of  London.  At  Captain  Roher's  rate  of  travelling 
Tromso  would  be  but  twenty-three  hours  from  the  Pole. 

These  figures  are,  of  course,  only  stated  as  possibilities  on  the  sup- 
position that  all  the  conditions  should  be  favorable,  but  by  no  means 
as  probable. 

What,  then,  are  the  probabilities  and  the  amount  of  risk  that  will 
attend  an  attempt  to  reach  the  Pole  by  an  aerial  route  ? 


AERIAL   EXPLORATION   OF  THE   ARCTIC   REGIONS.      211 

I  have  considered  the  subject  carefully,  and  discussed  it  with  many 
people  ;  the  result  of  such  reflection  and  conversation  is  a  conviction 
that  the  prevalent  popular  estimate  of  the  dangers  of  Commander 
Cheyne's  project  extravagantly  exaggerates  them  on  almost  all  con- 
tingencies. I  do  not  affirm  that  there  is  no  risk,  or  that  the  attempt 
should  be  made  with  only  our  present  practical  knowledge  of  the 
subject,  but  I  do  venture  to  maintain  that,  after  making  proper  pre- 
liminary practical  investigations  at  home,  a  judiciously  conducted 
aerostatic  dash  for  the  Pole  will  be  far  less  dangerous  than  the  Afri- 
can explorations  of  Livingstone,  Stanley,  and  others  that  have  been 
accomplished  and  are  proposed.  And  further,  that  a  long  balloon 
journey  starting  in  summer  time  from  Smith's  Sound,  or  other  suita- 
ble Arctic  station,  would  be  less  dangerous  than  a  corresponding  one 
started  from  London  ;  that  it  would  involve  less  risk  than  was  in- 
curred by  Messrs.  Holland,  Mason,  and  Green,  when  they  travelled 
from  Vauxhall  Gardens  to  Xassau. 

The  three  principal  dangers  attending  such  a  balloon  journey  are  : 
1st.  The  variability  of  the  wind.  2d.  The  risk  of  being  blown  out 
upon  the  open  ocean  beyond  the  reach  of  land.  3d.  The  utter  help- 
lessness of  the  aeronaut  during  all  the  hours  of  darkness.  I  will  con- 
sider these  seriatim  in  reference  to  Arctic  ballooning  versus  Vauxhall 
or  Crystal  Palace  ballooning. 

As  regards  the  first  danger,  Vauxhall  and  Sydenham  are  in  a  posi- 
tion of  special  disadvantage,  and  all  the  ideas  we  Englishmen  may 
derive  from  our  home  ballooning  experience  must  tend  to  exaggerate 
our  common  estimate  of  this  danger,  inasmuch  as  we  are  in  the 
midst  of  the  region  of  variable  winds,  and  have  a  notoriously  uncer- 
tain climate,  due  to  this  local  exaggeration  of  the  variability  of 
atmospheric  movements.  If  instead  of  lying  between  the  latitudes  of 
50°  and  60°,  where  the  N.  E.  Polar  winds  just  come  in  collision  with 
the  S.  W.  tropical  currents,  and  thereby  effect  our  national  atmos- 
pheric stir-about,  we  were  located  bet\veen  10°  and  30°  (where  the 
Canary  Islands  are,  for  example),  our  notions  on  the  subject  of  bal- 
loon travelling  would  be  curiously  different.  The  steadily  blowing 
trade-wind  would  long  ere  this  have  led  us  to  establish  balloon  mails 
to  Central  and  South  America,  and  balloon  passenger  expresses  for 
the  benefit  of  fast-going  people  or  luxurious  victims  of  sea-sickness. 
To  cross  the  Atlantic— three  thousand  miles— in  forty-eight  hours, 
would  be  attended  with  no  other  difficulty  than  the  cost  of  the  gas, 
and  that  of  the  return  carriage  of  the  empty  balloon. 

It  is  our  exceptional  meteorological  position  that  has  generated  the 
popular  expression  "  as  uncertain  as  the  wind."  "We  are  in  the  very 
centre  of  the  region  of  meteorological  uncertainties,  and  cannot  go 
far,  either  northward  or  southward,  without  entering  a  zone  of 
greater  atmospheric  regularity,  where  the  direction  of  the  wind  at  a 
given  season  may  be  predicted  with  more  reliability  than  at  home. 
The  atmospheric  movements  in  the  Arctic  regions  appear  to  be  re- 
markably regular  and  gentle  during  the  summer  and  winter  months, 
and  irregular  and  boisterous  in  spring  and  autumn.  A  warm  upper 
current  flows  from  the  tropics  toward  the  Pole,  and  a  cold  lower  one 
from  the  Arctic  circle  toward  the  equator.  Commander  Cheyne,  who 
has  practical  experience  of  these  Arctic  expeditions,  and  has  kept  an 
elaborate  log  of  the  wind,  etc.,  which  he  has  shown  me,  believes  that, 
by  the  aid  of  pilot  balloons  to  indicate  the  currents  at  various 


SCIENCE   IN   SHORT   CHAPTERS. 

heights,  and  by  availing  himself  of  these  currents,  he  may  reach  the 
Pole  and  return  to  his  ship,  or  so  near  as  to  be  able  to  reach  it  by 
travelling  over  the  ice  in  light  sledges  that  will  be  carried  for  the  pur- 
pose. In  making  any  estimate  of  the  risk  of  Arctic  aerostation,  we 
must  banish  from  our  minds  the  preconceptions  induced  by  our 
British  experience  of  the  uncertainties  of  the  wind,  and  only  con- 
sider the  atmospheric  actualities  of  the  Polar  regions,  so  far  as  we 
know  them. 

Let  us  now  consider  the  second  danger,  viz.  that  of  being  blown  out 
to  sea  and  there  remaining  until  the  leakage  of  gas  has  destroyed  tho 
ascending  power  of  the  balloon,  or  till  the  stock  of  food  is  consumed. 
A  glance  at  a  map  of  the  world  will  show  how  much  smaller  is  the 
danger  to  the  aeronaut  who  starts  from  the  head  of  Baffin's  Bay,  than 
that  which  was  incurred  by  those  who  started  from  Vauxhall  in  the 
Nassau  balloon,  or  by  Captain  Boher,  who  started  from  Paris.  Both 
of  these  had  the  whole  breadth  of  the  Atlantic  on  the  W.  and  S.  W., 
and  the  North  Sea  and  Arctic  Ocean  N.  and  N.  E.  The  Arctic  bal- 
loon, starting  from  Smith's  Sound  or  thereabout,  with  a  wind  from 
the  south  (and  without  such  a  wind  the  start  would  not,  of  course, 
be  made),  would,  if  the  wind  continued  in  the  same  direction, 
reach  the  Pole  in  a  few  hours  ;  in  seven  or  eight  hours  at  Eoher's 
speed  ;  in  fourteen  or  fifteen  hours  at  the  average  rate  made  by  the 
Nassau  balloon  in  a  "  moderate  breeze. "  Now  look  again  at  the  map 
and  see  what  surrounds  them.  Simply  the  continents  of  Europe, 
Asia,  and  America,  by  which  the  circumpolar  area  is  nearly  land- 
locked, with  only  two  outlets,  that  between  Norway  and  Greenland 
on  one  side,  and  the  narrow  channel  of  Behring's  Straits  on  the 
other.  The  wider  of  these  is  broken  by  Spitzbergen  and  Iceland, 
both  inhabited  islands,  where  a  balloon  may  descend  and  the  aero- 
nauts be  hospitably  received.  Taking  the  360  degrees  of  the  zone  be- 
tween the  70th  parallel  of  latitude  and  the  Arctic  circle,  320  are  land- 
locked and  only  40  open  to  the  sea  ;  therefore  the  chances  of  coming 
upon  land  at  any  one  part  of  this  zone  is  as  320  to  40  ;  but  with  a 
choice  of  points  for  descent  such  as  the  aeronauts  would  have  unless 
the  wind  blew  precisely  down  the  axis  of  the  opening,  the  chances 
would  be  far  greater.  If  the  wind  continued  as  at  starting,  they 
would  be  blown  to  Finland  ;  a  westerly  deflection  would  land  them 
in  Siberia,  easterly  in  Norway  ;  a  strong  E.  wind  at  the  later  stage  of 
the  trip  would  blow  them  back  to  Greenland. 

In  all  the  above  I  have  supposed  the  aeronauts  to  be  quite  help- 
less, merely  drifting  at  random  with  that  portion  of  the  atmosphere 
in  which  they  happened  to  be  immersed.  This,  however,  need  not 
be  the  case.  Within  certain  limits  they  have  a  choice  of  winds, 
owing  to  the  prevalence  of  upper  and  lower  currents  blowing  in 
different  and  even  in  opposite  directions.  Suppose,  for  example, 
they  find  themselves  N.  of  Spitzbergen,  where  "  Parry's  furthest  "  is 
marked  on  some  of  our  maps,  and  that  the  wind  is  from  the  N.  E., 
blowing  them  toward  the  Atlantic  opening.  They  would  then 
ascend  or  descend  in  search  of  a  due  N.  or  N.  by  W.  wind  that  would 
blow  them  to  Norway,  or  W.  N.  W.  to  Finland,  or  N,  W.  to  Siberia, 
or  due  E.  back  to  Greenland,  from  whence  they  might  rejoin  their 
ships.  One  or  other  of  these  would  almost  certainly  be  found.  A 
little  may  be  done  in  steering  a  balloon,  but  so  very  little  that  small 
reliance  should  be  placed  upon  it.  Only  in  a  very  light  wind  would 


AERIAL   EXPLORATION   OF  THE   ARCTIC    REGIONS.      213 

it  have  a  sensible  effect,  though  in  case  of  a  "  near  shave"  between 
landing,  say  at  the  Lot'odens  or  Iceland,  and  being  blown  out  to  sea, 
it  might  just  save  them. 

As  already  stated,  Commander  Cheyne  believes  in  the  possibility  of 
returning  to  the  ship,  and  bases  his  belief  on  the  experiments  he 
made  from  winter  quarters  in  Northumberland  Sound,  where  he 
inflated  four  balloons,  attached  to  them  proportionately  different 
weights,  and  sent  them  up  simultaneously.  They  were  borne  by 
diverse  currents  of  air  in  four  different  directions,  according  to  the  differ- 
ent altitudes,  viz.  N.  W.,  N.  E.,  S.  E.,  and  S.  W.,  "  thus  proving  that 
in  this  case  balloons  could  be  sent  in  any  required  direction  by 
ascending  to  the  requisite  latitude.  The  war  balloon  experiments  at 
Woolwich  afford  a  practical  confirmation  of  this  important  feature  iri 
aerostation."  Cheyne  proposes  that  one  at  least  of  the  three  bal- 
loons shall  be  a  rover  to  cross  the  unknown  area,  and  has  been  called 
a  madman  for  suggesting  this  merely  as  an  alternative  or  secondary 
route.  I  am  still  more  lunatic,  for  I  strongly  hold  the  opinion  that 
the  easiest  way  for  him  to  return  to  his  ship  will  be  to  drift  rapidly 
across  to  the  first  available  inhabited  land,  thence  come  to  England, 
and  sail  in  another  ship  to  rejoin  his  messmates  ;  carrying  with  him 
his  bird's-eye  chart,  that  will  demonstrate  once  for  all  the  pos- 
sibility or  impossibility  of  circumnavigating  Greenland,  or  of  sailing, 
or  sledging,  or  walking  to  the  Pole. 

The  worst  dilemma  would  be  that  presented  by  a  dead  calm,  and  it 
is  not  improbable  that  around  the  Pole  there  may  be  a  region  of  calms 
similar  to  that  about  the  Equator.  Then  the  feather-paddle  or  other 
locomotive  device  worked  by  man-power  would  be  indispensable.  Bet- 
ter data  than  we  at  present  possess  are  needed  in  order  to  tell  accu- 
rately what  may  thus  be  done.  Putting  various  estimates  one 
against  the  other,  it  appears  likely  that  five  miles  an  hour  may  be 
made.  Taking  turn  and  turn  about,  two  or  three  aeronauts  could 
thus  travel  fully  100  miles  per  day,  and  return  from  the  Pole  to  the 
ship  in  less  than  five  days. 

Or  take  the  improbable  case  of  a  circular  wind  blowing  round  the 
Pole,  as  some  have  imagined.  This  would  simply  demand  the  work- 
ing of  the  paddle  always  northward  in  going  to  the  Pole,  and  always 
southward  in  returning.  The  resultant  would  be  a  spiral  course 
winding  inward  in  the  first  case,  and  outward  in  the  second.  The 
northward  or  southward  progress  would  be  just  the  same  as  in  a 
calm  if  the  wind  were  truly  concentric  to  the  Pole.  Some  rough  ap- 
proximation to  such  currents  may  exist,  and  might  be  dealt  with  on 
this  principle. 

Let  us  now  consider  the  third  danger,  that  of  the  darkness.  The 
seriousness  of  this  may  be  inferred  from  the  following  description  of 
the  journey  of  the  Nassau  balloon,  published  at  the  time  :  "  It  seemed 
to  the  aeronauts  as  if  they  were  cleaving  their  way  through  an  inter- 
minable mass  of  black  marble  in  wrhich  they  were  imbedded,  and 
which,  solid  a  few  inches  before  them,  seemed  to  soften  as  they  ap- 
proached in  order  to  admit  them  still  further  within  its  cold  and 
dusky  enclosure.  In  this  way  they  proceeded  blindly,  as  it  may  well 
be  called,  until  about  3. 30  A.M.,  when  in  the  midst  of  the  impenetrable 
darkness  and  profound  stillness  an  unusual  explosion  issued  from  the 
machine  above,  followed  by  a  violent  rustling  of  the  silk,  and  all  th« 
signs  which  might  be  supposed  to  accompany  the  bursting  of  the  bal- 


214  SCIENCE  1$  SHOE!  CHAPI-EKS. 

loon.  The  car  was  violently  shaken.  A  second  and  a  third  explosion 
followed  in  quick  succession.  The  danger  seemed  immediate,  when 
suddenly  the  balloon  recovered  her  usual  form  and  stillness.  These 
alarming  symptoms  seemed  to  have  been  produced  by  collapsing  of 
the  balloon  under  the  diminished  temperature  of  the  upper  regions 
after  sunset,  and  the  silk  forming  into  folds  under  the  netting.  Now, 
when  the  guide  rope  informed  the  voyagers  that  the  balloon  was  too 
near  the  earth,  ballast  was  thrown  out,  and  the  balloon  rising  rapidly 
into  a  thinner  air  experienced  a  diminution  of  pressure,  and  conse- 
quent expansion  of  the  gas. 

"  The  cold  during  the  night  ranged  from  a  few  degrees  below  to 
the  freezing  point.  As  morning  advanced  the  rushing  of  waters  was 
heard,  and  so  little  were  the  aeronauts  aware  of  the  course  which 
.they  had  been  pursuing  during  the  night,  that  they  supposed  them- 
selves to  have  been  thrown  back  upon  the  shores  of  the  German 
Ocean,  or  about  to  enter  the  Baltic,  whereas  they  were  actually  over 
the  Rhine,  not  far  from  Coblentz." 

All  this  blind  drifting  for  hours,  during  which  the  balloon  may  be 
carried  out  to  sea,  and  opportunities  cf  safe  descent  may  be  lost,  is 
averted  in  an  Arctic  balloon  voyage,  which  would  be  made  in  the 
summer,  when  the  sun  never  sets.  There  need  be  no  break  in  the 
survey  of  the  ground  passed  over,  no  difficulty  in  pricking  upon  a 
chart  the  course  taken  and  the  present  position  at  any  moment. 
With  an  horizon  of  50  to  100  miles'  radius  the  approach  of  such  a 
danger  as  drifting  to  the  open  ocean  would  be  perceived  in  ample 
time  for  descent,  and,  as  a  glance  at  the  map  will  show,  this  danger 
cannot  occur  until  reaching  the  latitudes  of  inhabited  regions. 

The  Arctic  aeronauts  will  have  another  great  advantage  over  those 
who  ascend  from  any  part  of  England.  They  can  freely  avail  them- 
selves of  Mr.  Green's  simple  but  most  important  practical  invention 
— the  drag  rope.  This  is  a  long  and  rather  heavy  rope  trailing  on 
the  ground.  It  performs  two  important  functions.  First,  it  checks 
the  progress  of  the  balloon,  causing  it  to  move  less  rapidly  than  the 
air  in  which  it  is  immersed.  The  aeronaut  thus  gets  a  slight  breeze 
equivalent  to  the  difference  between  the  velocity  of  the  wind  and 
that  of  the  balloon's  progress.  He  may  use  this  as  a  fulcrum  to 
effect  a  modicum  of  steerage. 

The  second  and  still  more  important  use  of  the  drag  rope  is  the 
very  great  economy  of  ballast  it  achieves.  Suppose  the  rope  to  be 
1000  feet  long,  its  weight  equal  to  1  Ib.  for  every  ten  feet,  and  the 
balloon  to  have  an  ascending  power  of  50  Ibs.  It  is  evident  that  un- 
der these  conditions  the  balloon  will  retain  a  constant  elevation  of 
500  feet  above  the  ground  below  it,  and  that  500  feet  of  rope  will  trail 
upon  the  ground.  Thus,  if  a  mountain  is  reached  no  ballast  need  be 
thrown  away  in  order  to  clear  the  summit,  as  the  balloon  will  always 
lift  its  500  feet  of  rope,  and  thus  always  rise  with  the  up-slope  and 
descend  with  the  down-slope  of  hill  and  dale.  The  full  use  of  this 
simple  and  valuable  adjunct  to  aerial  travelling  is  prevented  in  such 
a  country  as  ours  by  the  damage  it  might  do  below,  and  the  tempta- 
tion it  affords  to  mischievous  idiots  near  whom  it  may  pass. 

In  the  course  of  many  conversations  with  various  people  on  this 
subject  I  have  been  surprised  at  the  number  of  educated  men  and 
women  who  have  anticipated  with  something  like  a  shudder  the  terri- 
ble cold  to  which  the  poor  aeronauts  will  be  exposed. 


AERIAL   EXPLORATION   OF   THE   ARCTIC   REGIONS.      215 

This  popular  delusion  which  pictures  the  Arctic  regions  as  the 
abode  of  perpetual  freezing,  is  so  prevalent  and  general,  that  some 
explanation  is  demanded. 

The  special  characteristic  of  Arctic  climate  is  a  cold  and  long 
winter  and  a  short  and  hot  summer.  The  winter  is  intensely  cold 
simply  because  the  sun  never  shines,  and  the  summer  is  very  hot  be- 
cause the  sun  is  always  above  the  horizon,  and,  unless  hidden  by 
clouds  or  mist,  is  continually  shining.  The  summer  heat  of  Siberia 
is  intense,  and  the  vegetation  proportionately  luxuriant.  I  have 
walked  over  a  few  thousand  miles  in  the  sunny  South,  but  never  was 
more  oppressed  with  the  heat  than  in  walking  up  the  Tromsdal  to 
visit  an  encampment  of  Laplanders  in  the  summer  of  1856. 

On  the  17th  July  I  noted  the  temperature  on  board  the  steam 
packet  when  we  were  about  three  degrees  north  of  the  Arctic  circle. 
It  stood  at  77°  well  shaded  in  a  saloon  under  the  deck  ;  it  was  92°  in 
the  "  rok  lugar,"  a  little  smoking  saloon  built  on  deck  ;  and  108°  in 
the  sun  on  deck.  This  was  out  at  sea,  where  the  heat  was  less  op- 
pressive than  on  shore.  The  summers  of  Arctic  Norway  are  very  vari- 
able on  account  of  the  occasional  prevalence  of  misty  weather.  The 
balloon  would  be  above  much  of  the  mist,  and  would  probably  enjoy 
a  more  equable  temperature  during  the  twenty-four  hours  than  in 
any  part  of  the  world  where  the  sun  sets  at  night. 

I  am  aware  that  the  above  is  not  in  accordance  with  the  experience 
of  the  Arctic  explorers  who  have  summered  in  such  places  as  Smith's 
Sound.  I  am  now  about  to  perpetrate  something  like  a  heresy  by 
maintaining  that  the  summer  climate  there  experienced  by  these  ex- 
plorers is  quite  exceptional,  is  not  due  to  the  latitude,  but  to  causes 
that  have  hitherto  escaped  the  notice  of  the  explorers  themselves  and 
of  physical  geographers  generally.  The  following  explanation  will 
probably  render  my  view  of  this  subject  intelligible  : 

As  already  stated,  the  barrier  fringe  that  has  stopped  the  progress  of 
Arctic  explorers  is  a  broken  mountainous  shore  down  which  is  pouring 
a  multitude  of  glaciers  into  the  sea.  The  ice  of  these  glaciers  is,  of 
course,  fresh-water  ice.  Now,  we  know  that  when  ice  is  mixed  with 
salt  water  we  obtain  what  is  called  "  a  freezing  mixture" — a  reduction 
of  temperature  far  below  the  freezing  point,  due  to  the  absorption^of 
heat  by  the  liquefaction  of  the  ice.  Thus  the  heat  of  the  continu- 
ously shining  summer  sun  at  this  particular  part  of  the  Arctic  region  is 
continuously  absorbed  by  this  powerful  action,  and  a  severity  quite 
exceptional  is  thereby  produced.  Every  observant  tourist  who  has 
crossed  an  Alpine  glacier  on  a  hot  summer  day  has  felt  the  sudden 
change  of  climate  that  he  encounters  on  stepping  from  terra  firma  on 
to  the  ice,  and  in  which  he  remains  immersed  as  long  as  he  is  on  the 
glacier.  How  much  greater  must  be  this  depression  of  temperature, 
where  the  glacier  ice  is  broken  up  and  is  floating  in  sea-water,  to  pro- 
duce  a  vast  area  of  freezing  mixture,  which  would  speedily  biing  the 
hottest  blasts  from  the  Sahara  down  to  many  degrees  below  the  freez- 
ing point. 

A  similar  cause  retards  the  beginning  of  summer  in  Arctic  Norway 
and  in  Finland  and  Siberia.  So  long  as  the  winter  snow  remains  un- 
melted,  i.e.  till  about  the  middle  or  end  of  June,  the  air  is  kept  cold, 
all  the  solar  heat  being  expended  in  the  work  of  thawing.  This  work 
finished,  then  the  warming  power  of  a  non-setting  sun  becomes  evi- 
dent, and  the  continuously  accumulating  heat  of  his  rays  displays  its 


216  SCIENCE   IN"   SHOUT   CHAPTERS. 

remarkable  effect  on  vegetable  life,  and  everything  capable  of  being 
•warmed.  These  peculiarities  of  Arctic  climate  must  become  exag- 
gerated as  the  Pole  is  approached,  the  winter  cold  still  more  intense, 
and  the  accumulation  of  summer  heat  still  greater.  In  the  neighbor- 
hood of  the  North  Cape,  where  these  contrasts  astonish  English 
visitors,  where  inland  summer  travelling  becomes  intolerable  on 
account  of  the  clouds  of  mosquitoes,  the  continuous  sunshine  only 
lasts  from  May  llth  to  August  1st.  At  the  North  Pole  the  sun  would 
visibly  remain  above  the  horizon  during  about  seven  months— from 
the  first  week  in  March  to  the  first  week  in  October  (this  includes  the 
effect  of  refraction  and  the  prolonged  summer  of  the  northern  hemi- 
sphere due  to  the  eccentricity  of  the  earth's  orbit). 

This  continuance  of  sunshine,  in  ppite  of  the  moderate  altitude  of 
the  solar  orb,  may  produce  a  very  genial  summer  climate  at  the  Pole. 
I  say  "  may,"  because  mere  latitude  is  only  one  of  the  elements  of 
climate,  especially  in  high  latitudes.  Very  much  depends  upon  sur- 
face configuration  and  the  distribution  of  land  and  water.  The 
region  in  which  our  Arctic  expedition  ships  have  been  ice-bound 
combines  all  the  most  unfavorable  conditions  of  Arctic  summer  cli- 
mate. It  is  extremely  improbable  that  those  conditions  are  main- 
tained all  the  way  to  the  Pole.  We  know  the  configuration  of  Arctic 
Europe  and  Arctic  Asia,  that  they  are  masses  of  land  spreading  out 
northward  round  the  Arctic  circle  and  narrowing  southward  to  angu- 
lar terminations.  The  southward  configuration  and  northward  out- 
spreading of  North  America  are  the  same,  but  we  cannot  follow  the 
northern  portion  to  its  boundary  as  we  may  that  of  Europe  and  Asia, 
both  of  which  terminate  in  an  Arctic  Ocean.  Greenland  is  remarka- 
bly like  Scandinavia  ;  Davis's  Strait,  Baffin's  Bay,  and  Smith's  Sound 
corresponding  with  the  Baltic  and  the  Gulf  of  Bothnia.  The  deep 
fiords  of  Greenland,  like  those  of  Scandinavia,  are  on  its  western 
side,  and  the  present  condition  of  Greenland  corresponds  to  that  of 
Norway  during  the  milder  period  of  the  last  glacial  epoch.  If  the 
analogy  is  maintained  a  little  further  north  than  our  explorers  have 
yet  reached  we  must  come  upon  a  Polar  sea,  just  as  we  come  upon 
the  White  Sea  and  the  open  Arctic  Ocean  if  we  simply  travel  between 
400  and  500  miles  due  north  from  the  head  of  the  frozen  Gulf  of 
Bothnia. 

Such  a  sea,  if  unencumbered  with  land  ice,  will  supply  the  most 
favorable  conditions  for  a  genial  Arctic  summer,  especially  if  it  be 
dotted  with  islands  of  moderate  elevation,  which  the  analogies  of 
the  known  surroundings  render  so  very  probable.  Such  islands  may 
be  inhabited  by  people  who  cannot  reach  us  on  account  of  the  barrier 
wall  that  has  hitherto  prevented  us  from  discovering  them.  Some 
have  even  supposed  that  a  Norwegian  colony  is  there  imprisoned. 
Certainly  the  early  colonists  of  Greenland  have  disappeared,  and 
their  disappearance  remains  unexplained.  They  may  have  wandered 
northward,  mingled  with  the  Esquimaux,  and  have  left  descendants 
in  this  unknown  world.  If  any  of  Franklin's  crew  crawled  far 
enough  they  may  still  be  with  them,  unable  to  return. 

In  reference  to  these  possibilities  it  should  be  noted  that  a  barrier 
fringe  of  mountainous  land  like  that  of  Greenland  and  Arctic 
America  would  act  as  a  condensing  ground  upon  the  warm  air  flowing 
from  the  soutk,  and  would  there  accumulate  the  heavy  snows  and 
consequent  glaciers,  just  as  our  western  hiUs  take  so  much  of  the  rain 


AERIAL   EXPLORATION   OF   THE    ARCTIC    REGIONS.      217 

from  the  vapor-laden  winds  of  the  Atlantic.  The  snowfall  immedi- 
ately round  the  Pole  would  thus  be  moderated,  and  the  summer 
begin  so  much  earlier. 

I  have  already  referred  to  the  physical  resemblances  of  Baffin's  Bay, 
Smith's  Sound,  etc.,  to  the  Baltic*  the  Gulf  of  Bothnia,  and  Gulf  of 
Finland.  These  aro  frozen  every  winter,  but  the  Arctic  Ocean  due 
north  of  them  is  open  all  the  winter,  and  every  winter.  The  hardy 
Norse  fishermen  are  gathering  their  chief  harvest  of  codfish  in  the 
open  sea  around  and  beyond  the  North  Cape,  Nordkyn,  etc.,  at  the 
very  time  when  the  Russian  fleet  is  hopelessly  frozen  up  in  the  Gulf 
of  Finland.  But  how  far  due  north  of  this  frozen  Baltic  are  these 
open-sea  fishing  banks  ?  More  than  14  degrees — more  than  double 
the  distance  that  lies  between  the  winter  quarters  of  some  of  our 
ships  in  Smith's  Sound  and  the  Pole  itself.  This  proves  how  greatly 
physical  configuration  and  oceanic  communication  may  oppose  the 
climatic  influences  of  mere  latitude.  If  the  analogy  between  Baffin',* 
Bay  and  the  Baltic  is  complete,  a  Polar  sea  will  be  found  that  is  open 
in  the  summer  at  least. 

On  the  other  hand,  it  may  be  that  ranges  of  mountains  covered 
with  perpetual  snow,  and  valleys  piled  up  with  huge  glacial  accumu- 
lations, extend  all  the  way  to  the  Pole,  and  thus  give  to  our  globe  an 
Arctic  ice-cap  like  that  displayed  on  the  planet  Mars.  This,  how- 
ever, is  very  improbable,  for,  if  it  were  the  case,  we  ought  to  find  a 
circumpolar  ice-wall  like  that  of  the  Antarctic  regions  ;  the  Arctic 
Ocean  beyond  the  North  Cape  should  be  crowded  with  icebergs  in- 
stead of  being  open  and  iceless  all  the  year  round.  With  such  a  con- 
figuration the  ice-wall  should  reach  Spitzbergen  and  stretch  across  to 
Nova  Zembla  ;  but,  instead  of  this,  we  have  there  such  an  open 
stretch  of  Arctic  water,  that  in  the  summer  of  1876  Captain  Kjelsen, 
of  Tromso,  sailed  in  a  whaler  to  lat.  81°  30'  without  sighting  ice.  He 
was  then  but  510  geographical  miles  from  the  Pole,  with  open  sea 
right  away  to  his  north  horizon,  and  nobody  can  say  how  much 
farther. 

These  problems  may  all  be  solved  by  the  proposed  expedition. 
The  men  are  ready  and  willing  ;  one  volunteer  has  even  promised 
£1000  on  condition  that  he  shall  be  allowed  to  have  a  seat  in  one  of 
the  balloons.  All  that  is  wanted  are  the  necessary  funds,  and  the 
amount  required  is  but  a  small  fraction  of  what  is  annually  expended 
at  our  race-courses  upon  villanous  concoctions  of  carbonic  acid  and 
methylated  cider  bearing  the  name  of  "  champagne." 

Arrangements  are  being  made  to  start  next  May,  but  in  the  mean- 
time many  preliminary  experiments  are  required.  One  of  these,  con- 
cerning winch  I  have  been  boring  Commander  Cheyne  and  the  com- 
mittee, is  a  thorough  and  practical  trial  of  the  staying  properties  of 
hydrogen  gas  when  confined  in  given  silken  or  other  fabrics  sat- 
urated with  given  varnishes.  We  are  still  ignorant  on  this  funda- 
mental point.  We  know  something  about  coal  gas,  but  little  or  noth- 
ing of  the  hydrogen,  such  as  may  be  used  in  the  forthgoing  expedi- 
tion. Its  exosmosis,  as  proved  by  Graham,  depends  upon  its  adhe- 
sion to  the  surface  of  the  substance  confining  it.  Every  gas  has  its 
own  specialty  in  this  respect,  and  a  membrane  that  confines  a  hy- 
drocarbon like  coal  gas  may  be  very  unsuitable  for  pure  hydrogen, 
or  vice  versa.  Hydrogen  passes  through  hard  steel,  carbonic  oxide 
through  recWiot  iron  plates,  and  so  on  with  other  gases.  They  are 


218  SCIENCE   IN   SHORT   CHAPTERS. 

guilty  of  most  improbable  proceedings  in  the  matter  of  penetrating 
apparently  impenetrable  substances. 

The  safety  of  the  aeronauts  and  the  success  of  the  aerial  explora- 
tion primarily  depend  upon  the  length  of  time  that  the  balloons  can 
be  kept  afloat  in  the  air. 

A  sort  of  humanitarian  cry  has  been  raised  against  this  expedition, 
on  the  ground  that  unnaturally  good  people  (of  whom  we  now  meet 
so  many)  should  not  be  guilty  of  aiding  and  abetting  a  scheme  that 
may  cause  the  sacrifice  of  human  life.  These  kind  friends  may  bi 
assured  that,  in  spite  of  their  scruples,  the  attempt  will  be  made  b} 
men  who  share  none  of  their  fears,  unless  the  preliminary  experi- 
ments prove  that  a  balloon  cannot  be  kept  up  long  enough.  There- 
fore the  best  way  to  save  their  lives  is  to  subscribe  at  once  for  the 
preliminary  expense  of  making  these  trials,  which  will  either  discover 
means  of  travelling  safely,  or  demonstrate  the  impossibility  of  such 
ballooning  altogether.  Such  experiments  will  have  considerable 
scientific  value  in  themselves,  and  may  solve  other  problems  besides 
those  of  Arctic  exploration. 

Why  not  apply  balloons  to  African  exploration  or  the  crossing  of 
Australia  ?  The  only  reply  to  this  is  that  we  know  too  little  of  the 
practical  possibilities  of  such  a  method  of  travelling  when  thus  ap- 
plied. Hitherto  the  balloon  has  only  been  a  sensational  toy.  We 
know  well  enough  that  it  cannot  be  steered  in  a  predetermined  line, 
i.e.  from  one  point  to  another  given  point,  but  this  is  quite  a  different 
problem  from  sailing  over  a  given  surface  of  considerable  area.  This 
can  be  done  to  a  certain  extent,  but  we  want  to  know  definitely  to 
what  extent,  and  what  are  the  limits  of  reliability  and  safety.  With 
this  knowledge,  and  its  application  by  the  brave  and  skilful  men 
who  are  so  eager  to  start,  the  solution  of  the  Polar  mystery  assumes 
a  new  and  far  more  hopeful  phase  than  it  has  ever  before  presented. 

THE   ANGLO-AMEKICAN   AECTIC   EXPEDITION. 

Commander  Cheyne  has  gone  to  America  to  seek  the  modest 
equipment  that  his  own  countrymen  are  unable  to  supply.  He  pro- 
poses now  that  his  expedition  shall  be  "  Anglo- American."  I  have 
been  asked  to  join  an  Arctic  Council,  to  co-operate  on  this  side,  and 
have  refused  on  anti-patriotic  grounds.  As  a  member  of  the  former 
Arctic  Committee,  I  was  so  much  disgusted  with  the  parsimony  of 
our  millionaires  and  the  anti-geographical  conduct  of  the  Savile  Eow 
Mutual  Admiration  Society,  that  I  heartily  wish  that  in  this  matter 
our  American  grandchildren  may  "  lick  the  Britishers  quite  com- 
plete. "  It  will  do  us  much  good. 

My  views,  expressed  in  the  Gentleman's  Magazine  of  July,  1880,  and 
repeated  above,  remain  unchanged,  except  in  the  direction  of  con- 
firmation and  development.  I  still  believe  that  an  enthusiastic, 
practically  trained,  sturdy  Arctic  veteran,  who  has  endured  hardship 
both  at  home  and  abroad,  whose  craving  eagerness  to  reach  the  Pole 
amounts  to  a  positive  monomania,  who  lives  for  this  object  alone, 
and  is  ready  to  die  for  it,  who  will  work  at  it  purely  for  the  work's 
sake — will  be  the  right  man  in  the  right  place  when  at  the  head  of  a 
modestly  but  efficiently  equipped  Polar  expedition,  especially  if 
Lieutenant  Schwatka  is  his  second  in  command. 

They  will  not  require  luxurious  saloons,  nor  many  cases  of  cham- 
pagne ;  they  will  care  but  little  for  amateur  theatricals  ;  they  will 


AERIAL   EXPLORATION   OF   THE   ARCTIC    REGIONS.      219 

follow  the  naval  traditions  of  the  old  British  "  sea-dogs"  rsither  than 
those  of  our  modern  naval  lap-dogs,  and  will  not  turn  back  after  a 
first  struggle  with  the  cruel  Arctic  ice,  even  though  they  should  sup- 
pose it  to  be  "  paleocrystic. " 

MR.    WALTER   POWELL. 

Scientific  aerostation  has  lost  its  most  promising  expert  by  the  un- 
timely death  of  Walter  Powell.  He  was  not  a  mere  sensational  bal- 
looner,  nor  one  of  those  dreamers  who  imagine  they  can  invent  flying 
machines,  or  steer  balloons  against  the  wind  by  mysterious  electrical 
devices  or  by  mechanical  paddles,  fan-wheels,  or  rudders. 

He  perfectly  understood  that  a  balloon  is  at  the  mercy  of  atmos- 
pheric currents  and  must  drift  with  them,  but  nevertheless  he  re- 
garded it  as  a  most  promising  instrument  for  geographical  research. 
I  had  a  long  conference  with  him  on  the  subject  in  August  last,  when 
he  told  me  that  the  main  objects  of  the  ascents  he  had  already  made, 
and  should  be  making  for  some  little  time  forward,  were  the  acquisi- 
tion of  practical  skill,  and  of  further  knowledge  of  atmospheric  cur- 
rents ;  after  which  he  should  make  a  dash  at  the  Atlantic  with  the 
intent  of  crossing  to  America. 

On  my  part,  I  repeated  with  further  argument  what  I  have  already 
urged  on  page  113  of  the  Gentleman's  Magazine  for  July,  1880,  viz.  the 
primary  necessity  of  systematic  experimental  investigation  of  the  rate 
of  exosmosis  (oozing  out)  of  the  gas  from  balloons  made  of  different 
materials  and  variously  varnished. 

Professor  Graham  demonstrated  that  this  molecular  permeation  of 
gases  and  liquids  through  membranes  mechanically  air-tight,  depends 
upon  the  adhesive  affinities  of  particular  solids  for  other  particular 
fluids,  and  these  affinities  vary  immensely,  their  variations  depend- 
ing on  chemical  differences  rather  than  upon  mechanical  impermea- 
bility. My  project  to  attach  captive  balloons  of  small  size  to  the  roof 
of  the  Polytechnic  Institution,  holding  them  by  a  steel-yard  that 
should  indicate  the  pull  due  to  their  ascending  power,  and  the  rate 
of  its  decline  according  to  the  composition  of  the  membrane,  was 
heartily  approved  by  Mr.  Powell,  and,  had  the  Polytechnic  survived, 
would  have  been  carried  out,  as  it  would  have  served  the  double  pur- 
pose  of  scientific  investigation  and  of  sensational  advertisement  for 
the  outside  public. 

If  the  aeronaut  were  quite  clear  on  this  point — could  calculate 
accurately  how  long  his  balloon  would  float — he  might  venture  with 
deliberate  calculation  on  journeys  that  without  such  knowledge  are 
mere  exploits  of  blind  daring. 

The  varnishes  at  present  used  are  all  permeable  by  hydjoj.-en  gas 
and  hydrocarbon  coal  gas,  as  might  be  expected,  h  priori,  from  the 
fact  that  they  are  themselves  solid  hydrocarbons,  soluble  in  other 
liquid  or  gaseous  hydrocarbons.  Nothing,  as  far  as  I  can  learn,  has 
yet  been  done  with  silicic  or  boracic  varnishes,*  which  are  theoreti- 
cally impermeable  by  hydrogen  and  its  carbon  compounds  ;  but 
whether  they  are  practically  so  under  ballooning  conditions,  and  can 
be  made  sufficiently  pliable  and  continuous,  are  questions  only  to  be 

*  Since  the  above  was  written  I  have  made  some  experiments  with  a  solution  of 
sholl^c  in  borax  (obtained  by  long  boiling,  and  hereby  claim  the  invention  of  its 
application  to  this  purpose,  in  order  to  prevent  anybody  from  patenting  it.  I  shall 
not  do  eo  myself. 


220  SCIENCE   Itf   SHORT   CHAPTERS. 

solved  by  practical  experiments  of  the  kind  above  named.  Now  that 
the  best  man  for  making  these  experiments  is  gone,  somebody  else 
should  undertake  them.  Unfortunately,  they  must  of  necessity  be 
rather  expensive. 


CHAPTER  XXVII. 

THE   LIMITS   OF   OUR   COAL   SUPPLY.* 

ESTIMATING  the  actual  consumption  of  coal  for  home  use  in  Great 
Britain  at  110  millions  of  tons  per  annum,  a  rise  of  eight  shillings 
per  ton  to  consumers  is  equivalent  to  a  tax  of  44  millions  per  animm. 
These  are  the  figures  taken  by  Sir  William  Armstrong  in  his  address 
at  Newcastle  last  February.  As  the  recent  abnormal  rise  in  the  value 
of  coal  has  amounted  to  more  than  this,  consumers  have  been  paying 
at  some  periods  above  a  million  per  week  as  premium  on  fuel,  even 
after  making  fair  deduction  for  the  rise  of  price  necessarily  due  to 
the  diminishing  value  of  gold. 

Are  we,  the  consumers  of  coal,  to  write  off  all  this  as  a  dead  loss, 
or  have  we  gained  any  immediate  or  prospective  advantage  that  may 
be  deducted  from  the  bad  side  of  the  account  ?  I  suspect  that  we 
shall  gain  sufficient  to  ultimately  balance  the  loss,  and,  even  after 
that,  to  leave  something  on  the  profit  side. 

The  abundance  of  our  fuel  has  engendered  a  shameful  wastefulness 
that  is  curiously  blind  and  inconsistent.  As  a  typical  example  of 
this  inconsistency,  I  may  mention  a  characteristic  incident.  A  party 
of  young  people  were  sitting  at  supper  in  the  house  of  a  colliery 
manager.  Among  them  was  the  vicar  of  the  parish,  a  very  jovial  and 
genial  man,  but  most  earnest  withal  in  his  vocation.  Jokes  and 
banterings  were  freely  flung  across  the  table,  and  no  one  enjoyed  the 
fun  more  heartily  than  the  vicar  ;  but  presently  one  unwary  youth 
threw  a  fragment  of  bread- crust  at  his  opposite  neighbor,  and  thus 
provoked  retaliation.  The  countenance  of  the  vicar  suddenly 
changed,  and  in  stern  clerical  tones  he  rebuked  the  wickedness  of 
thus  wasting  the  bounties  of  the  Almighty.  A  general  silence  fol- 
lowed, and  a  general  sense  of  guilt  prevailed  among  the  revellers. 
At  the  same  time,  and  in  the  same  room,  a  blazing  fire,  in  an  ill-con- 
structed open  fireplace,  was  glaring  reproachfully  at  all  the  guests, 
but  no  one  heeded  the  immeasurably  greater  and  utterly  irreparable 
waste  that  was  there  proceeding.  To  every  unit  of  heat  that  was 
fully  utilized  in  warming  the  room,  there  were  eight  or  nine  passing 
up  the  chimney  to  waste  their  energies  upon  the  senseless  clouds  and 
boundless  outer  atmosphere.  A  large  proportion  of  the  vicar's  pa- 
rishioners are  colliers,  in  whose  cottages  huge  fires  blaze  most  waste- 
fully  all  day,  and  are  left  to  burn  all  night  to  save  the  trouble  of 
relighting.  The  vicar  diligently  visits  these  cottages,  and  freely 
admonishes  where  he  deems  it  necessary  ;  yet  he  sees  in  this  general 
waste  of  coal  no  corresponding  sinfulness  to  that  of  wasting  bread. 
Why  is  he  so  blind  in  one  direction,  while  his  moral  vision  is  so 

*  Wriltcn  during  the  coal  famine  of  1872-73. 


THE   LIMITS   OF   OUR   COAL   SUPPLY.  221 

microscopic  in"  the  other  ?    Why  are  nearly  all  Englishmen  and  Eng- 
lishwomen as  inconsistent  as  the  vicar  in  this  respect  ? 

There  are  doubtless  several  combining  reasons  for  this,  but  I  sus- 
pect that  the  principal  one  is  the  profound  impression  which  we 
have  inherited  from  the  experience  and  traditions  of  the  horrors  of 
bread-famine.  A  score  of  proverbs  express  the  important  practical 
truth  that  we  rarely  appreciate  any  of  our  customary  blessings  until 
•we  have  tasted  the  misery  of  losing  them.  Englishmen  have  tasted 
the  consequences  of  approximate  exhaustion  of  the  national  grain 
store,  but  have  never  been  near  to  the  exhaustion  of  the  national 
supply  of  coal. 

I  therefore  maintain  most  seriously  that  we  need  a  severe  coal  fam- 
ine, and  if  all  the  colliers  of  the  United  Kingdom  were  to  combine 
for  a  simultaneous  winter  strike  of  about  three  or  six  months'  dura- 
tion, they  might  justly  be  regarded  as  unconscious  patriotic  martyi  s, 
like  soldiers  slain  upon  a  battle-field.  The  evils  of  such  a  thorough 
famine  would  be  very  sharp,  and  proportionally  beneficent,  but  only 
temporary  ,  there  would  not  be  time  enough  for  manufacturing  rivals 
to  sink  pits,  and  at  once  erect  competing  iron-works  ;  but  the  whole 
world  would  partake  of  our  calamity,  and  the  attention  of  all  mankind 
would  be  aroTised  to  the  sinfulness  of  wasting  coal.  Six  months  of 
compulsory  wood  and  peat  fuel,  with  total  stoppage  of  iron  supplies, 
would  convince  the  people  of  these  islands  that  waste  of  coal  is  even 
more  sinful  than  waste  of  bread — would  lead  us  to  reflect  on  the  fact 
that  our  stock  of  coal  is  a  definite  and  limited  quantity  that  was 
placed  in  the  present  storehouse  long  before  human  beings  came 
upon  the  earth  ;  that  every  ton  of  coal  that  is  wasted  is  lost  forever, 
and  cannot  be  replaced  by  any  human  effort,  while  bread  is  a  pro- 
duct of  human  industry,  and  its  waste  may  be  replaced  l>y  additional 
human  labor  ;  that  the  sin  of  bread-wasting  does  admit  of  agricultural 
atonement,  while  there  is  no  form  of  practical  repentance  that  can 
positively  and  directly  replace  a  hundredweight  of  wasted  coal. 

Nothing  short  of  the  practical  and  impressive  lesson  of  bitter  want 
is  likely  to  drive  from  our  households  that  wretched  fetish  of  British 
adoration,  the  open  "  Englishman's  fireside."  Keason  seems  power- 
less against  the  superstition  of  this  form  of  fire-worship.  Tell  one 
of  the  idolaters  that  his  household  god  is  wasteful  and  extravagant, 
that  five  sixths  of  the  heat  from  his  coal  goes  up  the  chimney,  and  he 
replies,  "  I  don't  care  if  it  does  ;  I  can  afford  to  pay  for  it.  I  like  to 
see  the  fire,  and  have  the  right  to  waste  what  is  my  own."  Tell  him 
that  healthful  ventilation  is  impossible  while  the  lower  part  of  a 
room  opens  widely  into  a  heated  shaft,  that  forces  currents  of  cold 
air  through  doors  and  window  leakages,  which  unite  to  form  a  per- 
petual chilblain  stratum  on  the  floor,  and  leaves  all  above  the  mantel- 
piece comparatively  stagnant.  Tell  him  that  no  such  things  as 
"  draughts"  should  exist  in  a  properly  warmed  and  ventilated  house, 
and  that  even  with  a  thermometer  at  zero  outside,  every  part  of  a 
well-ordered  apartment  should  be  equally  habitable,  instead  of  merely 
a  semicircle  about  the  hearth  of  the  fire-worshipper  ;  he  shuts  his 
ears,  locks  up  his  understanding,  because  his  grandfather  and  grand- 
mother believed  that  the  open-mouthed  chimney  was  the  one  and 
only  true  English  means  of  ventilation. 

But  suppose  we  were  to  say,  "  You  love  a  cheerful  blaze,  can  afford 
to  pay  for  it,  and  therefore  care  not  how  much  coal  you  waste  in  ob- 


2^2  SCIENCE   IN   SHORT   CHAPTERS. 

taining  it.  We  also  love  a  cheerful  blaze,  but  have  a  great  aversion 
to  coal-smoke  and  tarry  vapors  ;  and  we  find  that  we  can  make  a 
beautiful  fire,  quite  inoffensive  even  in  the  middle  of  the  room,  pro- 
vided we  feed  it  with  stale  quartern  loaves.  We  know  that  such  fuel 
is  expensive,  but  can  afford  to  pay  for  it,  and  choose  to  do  so." 
Would  he  not  be  shocked  at  the  sight  of  the  blazing  loaves,  if  this 
extravagance  were  carried  out  ? 

This  popular  inconsistency  of  disregarding  the  waste  of  a  valuable 
and  necessary  commodity,  of  which  the  supply  is  limited  and  un- 
renewable,  while  we  have  such  proper  horror  of  wilfully  wasting 
another  similar  commodity  which  can  be  annually  replaced  as  long 
as  man  remains  in  living  contact  with  the  earth,  will  gradually  pass 
away  when  rational  attention  is  directed  to  the  subject.  If  the  recent 
very  mild  suggestion  of  a  coal-famine  does  something  toward  placing 
coal  on  a  similar  pedestal  of  popular  veneration  to  that  which  is  held 
by  the  "  staff  of  life,"  the  million  a  week  that  it  has  cost  the  coal 
consumer  will  have  been  profitably  invested. 

Many  who  were  formerly  deaf  to  the  exhortations  of  fuel  econo- 
mists are  now  beginning  to  listen.  Forty  shillings  per  ton  has  acted 
like  an  incantation  upon  the  spirit  of  Count  Runiford.  After  an 
oblivion  of  more  than  eighty  years,  his  practical  lessons  have  again 
sprung  up  among  us.  Some  are  already  inquiring  how  he  managed 
to  roast  112  Ibs.  of  beef  at  the  Foundling  Hospital  with  22  Ibs.  of 
coal,  and  to  use  the  residual  heat  for  cooking  the  potatoes,  and  why 
it  is  that  with  all  our  boasted  progress  we  do  not  now,  in  the  latter 
third  of  the  nineteenth  century,  repeat  that  which  he  did  in  the 
eighteenth. 

The  fact  that  the  consumption  of  coal  in  London  during  the  first 
four  months  of  1873  has,  in  spite  of  increasing  population,  amounted 
to  49,707  tons  less  than  the  corresponding  period  of  1872,  shows  that 
some  feeble  attempts  have  been  made  to  economize  the  domestic 
consumption  of  fuel.  One  very  useful  result  of  the  recent  scarcity  of 
coal  has  been  the  awakening  of  a  considerable  amount  of  general  in- 
terest in  the  work  of  stock-taking,  a  tedious  process  which  improvi- 
dent people  are  too  apt  to  shirk,  but  which  is  quite  indispensable  to 
sound  business  proceedings  either  of  individuals  or  nations. 

There  are  many  discrepancies  in  the  estimates  that  have  been  made 
of  the  total  available  quantity  of  British  coal.  The  speculative  na- 
ture of  some  of  the  data  renders  this  inevitable,  but  all  authorities 
appear  to  agree  on  one  point,  viz.  that  the  amount  of  our  supplies 
will  not  be  determined  by  the  actual  total  quantity  of  coal  under  our 
feet,  but  by  the  possibilities  of  reaching  it.  This  is  doubtless  cor- 
rect, but  how  will  these  possibilities  be  limited,  and  what  is  the 
extent  or  range  of  the  limit  ?  On  both  these  points  I  venture  to  dis- 
agree with  the  eminent  men  who  have  so  ably  discussed  this  ques- 
tion. First,  as  regards  the  nature  of  the  limit  or  barrier  that  will 
stop  our  further  progress  in  coal-getting.  This  is  generally  stated  to 
be  the  depth  of  the  seams.  The  Royal  Commissioners  of  1870  base 
their  tables  on  the  quantity  of  available  coal  in  the  visible  and  con- 
cealed coal-fields  upon  the  assumption  that  4000  feet  is  the  limit  of 
possible  working.  This  limit  is  the  same  that  was  taken  by  Mr.  Hall 
ten  years  earlier.  Mr.  Hull,  in  the  last  edition  of  "  The  Coal  Fields 
of  Great  Britain,"  p.  326,  referring  to  Prof essor  Ramsay' s  estimate, 
says,  "  These  estimates  are  drawn  up  for  depths  down  to  4000  feet 


THE   LIMITS   OF   OUR   COAL   SUPPLY.  223 

below  the  surface,  and  even  beyond  this  limit  ;  but  with  this  latter 
quantity  it  is  scarcely  necessary  that  we  should  concern  ourselves." 
I  shall  presently  show  reasons  for  believing  that  the  time  may  ulti- 
mately arrive  when  we  shall  concern  ourselves  with  this  deep  coal, 
and  actually  get  it  ;  while,  on  the  other  hand,  that  remote  epoch  will 
be  preceded  by  another  period  of  practical  approximate  exhaustion 
of  British  coal  supply,  which  is  likely  to  arrive  long  before  we  reach 
a  working  depth  of  4000  feet. 

The  Royal  Commissioners  estimate  that  within  the  limits  of  4000 
feet  we  have  hundreds  of  square  miles  of  attainable  coal  capable  of 
yielding,  after  deducting  40  per  cent,  for  loss  in  getting,  etc.,  146,480 
millions  of  tons  ;  or,  if  we  take  this  with  Mr.  Hull's  deduction  of 
one  twentieth  for  seams  under  two  feet  in  thickness,  there  remains 
139,000  millions  of  tons,  which,  at  present  rate  of  consumption, 
would  last  about  1200  years.  But  the  rate  of  consumption  is  an- 
nually increasing,  not  merely  on  account  of  increasing  population, 
but  also  from  the  fact  that  mechanical  inventions  are  perpetually 
superseding  hand  labor,  and  the  source  of  power  in  such  cases  is 
usually  derived  from  coal.  This  consideration  induced  Professor 
Jevoiis,  in  1865,  to  estimate  that  between  1861  and  1871  the  consump- 
tion would  increase  from  83,500,000  tons  to  118,000,000  tons.  Mr. 
Hunt's  official  return  for  1871  shows  that  this  estimate  was  a  close 
approximation  to  the  truth,  the  actual  total  for  1871  having  been 
117,352,028  tons.  At  this  rate  of  an  arithmetical  increase  of  three 
and  a  half  tons  per  annum,  139,000  millions  of  tons  would  last  but 
250  years.  Mr.  Hull,  taking  the  actual  increase  at  three  millions  of 
tons  per  annum,  extends  it  to  276  years.  Hitherto  the  annual  in- 
crease has  followed  a  geometrical  rather  than  arithmetical  progress, 
and  those  who  anticipate  a  continuance  of  this  allow  us  a  much 
shorter  lease  of  our  coal  treasures.  Mr.  Price  Williams  maintain.* 
that  the  increase  will  proceed  in  a  diminishing  ratio  like  that  of  the 
increase  of  population  ;  and  upon  this  basis  he  has  calculated  that 
the  annual  consumption  will  amount  to  274  millions  of  tons  a  hundred 
years  hence,  and  the  whole  available  stock  of  coal  will  last  about  360 
years. 

The  latest  returns  show,  for  1872,  an  output  of  123,546,758  tons, 
which,  compared  with  1871,  gives  a  rate  of  increase  of  more  than 
double  the  estimate  of  Mr.  Hull,  and  indicate  that  prices  have  not  yet 
risen  sufficiently  to  check  the  geometrical  rate  of  increase.*  Mr. 
Hull  very  justly  points  out  the  omission  in  those  estimates  which  do 
not  "  take  into  account  the  diminishing  ratio  at  which  coal  must  be 
consumed  when  it  becomes  scarcer  and  more  expensive  ;"  but,  on 
the  other  hand,  he  omits  the  opposite  influence  of  increasing  prices 
on  production,  which  has  been  strikingly  illustrated  by  the  extraor- 
dinary number  of  new  coal-mining  enterprises  that  have  been 
launched  during  the  last  six  months.  If  we  continue  as  we  are  now 
proceeding,  a  practical  and  permanent  coal  famine  will  be  upon  us 
within  the  lifetime  of  many  of  the  present  generation.  By  such  a 
famine,  I  do  not  mean  an  actual  exhaustion  of  our  coal  seams  (which 
will  never  be  effected),  but  such  a  scarcity  and  rise  of  prices  as  shall 
annihilate  the  most  voracious  of  our  coal-consuming  industries,  those 

*  From  1870  to  18SO  the  amount  has  risen  from  110.431,192  to  146,818,022  tons  per 
annum,  un  average  increase  of  3,638,743  tons  per  annum. 


224  SCIENCE   IN   SHORT   CHAPTEE3. 

which  depend  upon  abundance  of  cheap  coal,  such  as  the  manufact- 
ure of  pig-iron,  etc.* 

The  action  of  increasing  prices  has  been  but  lightly  considered 
hitherto,  though  its  importance  is  paramount  in  determining  the 
limits  of  our  coal  supply  ;  I  even  venture  so  far  as  to  affirm  that  it  is 
not  the  depth  of  the  coal  seams,  not  the  increasing  temperature  nor 
pressure  as  we  proceed  downward,  nor  even  thinness  of  seam,  that 
will  practically  determine  the  limits  of  British  coal-getting,  but 
simply  the  price  per  ton  at  the  pit's  mouth. 

In  proof  of  this,  I  may  appeal  to  actual  practice.  Mr.  Hull  and 
others  have  estimated  the  working  limit  of  thinness  at  two  feet,  and 
agree  in  regarding  thinner  seams  than  this  as  unworkable.  This  is 
unquestionably  correct  so  long  as  the  getting  is  effected  in  the  usual 
manner.  A  collier  cannot  lie  down  and  hew  a  much  thinner  seam 
than  this,  if  he  works  as  colliers  work  at  present.  But  the  lead  and 
copper  miners  succeed  in  working  far  thinner  lodes,  even  down  to 
the  thickness  of  a  few  inches,  and  the  gold-digger  crushes  the  hardest 
component  of  the  earth's  crust  to  obtain  barely  visible  grains  of  the 
precious  metal.  This  extension  of  effort  is  entirely  determined  by 
market  value.  At  a  sufficiently  high  price  the  two-feet  limit  of  coal- 
getting  would  vanish,  and  the  collier  would  work  after  the  manner  of 
the  lead-miner. 

We  may  safely  apply  the  same  reasoning  to  the  limits  of  depth. 
The  4000-feet  limit  of  the  Royal  Commissioners  is  at  present  unattain- 
able, simply  because  the  immediately  prospective  price  of  coal  would 
not  cover  the  cost  of  such  deep  sinking  and  working  ;  but  as  prices 
go  up,  pits  will  go  down,  deeper  and  deeper  still. 

The  obstacles  which  are  assumed  to  determine  the  4000-feet  limit 
are  increasing  density  due  to  greater  pressure,  and  the  elevation  of 
temperature  which  proceeds  as  we  go  downward.  The  first  of  these 
difficulties  has,  I  suspect,  been  very  much  overstated,  if  not  alto- 
gether misunderstood  ;  though  it  is  but  fair  to  add  that  Mr.  Hull, 
who  most  prominently  dwells  upon  it,  does  so  with  all  just  and 
philosophic  caution.  He  says  that  "  it  is  impossible  to  speak  with 
certainty  of  the  effect  of  the  accumulative  weight  of  3000  or  4000  feet 
of  strata  on  mining  operations.  In  all  probability  one  effect  would 
be  to  increase  the  density  of  the  coal  itself,  and  of  its  accompanying 
strata,  so  as  to  increase  the  difficulty  of  excavating,"  and  he  con- 
cludes by  stating  that  "  in  the  face  of  these  two  obstacles— tempera- 
ture and  pressure,  ever  increasing  with  the  depth— I  have  considered 
it  Utopian  to  include  in  calculations  having  reference  to  coal  supply 
any  quantity,  however  considerable,  which  lies  at  a  greater  depth 
than  4000  feet.  Beyond  that  depth  I  do  not  believe  that  it  will  be 
found  practicable  to  penetrate.  Nature  rises  up,  and  presents  insur- 
mountable barriers."  f 

On  one  point  I  differ  entirely  from  Mr.  Hull,  viz.  the  conclusion 
that  the  increased  "  density  of  the  coal  itself  and  of  its  accompany- 
ing strata"  will  offer  any  serious  obstacle.  On  the  contrary,  there  is 

*  At  the  present  time  (1882)  we  are  receiving  the  excessive  supplies  consequent 
upon  the  opening  of  new  pits  that,  under  the  Ptimnlus  of  high  prices,  were  in  the 
course  of  sinkinsr  when  the  above  was  written.  Hence  the  present  low  prices. 
Presently  the  annual  increase  of  consumption  will  overtake  this  increased  supply, 
and  another  "coal  famine"  like  that  then  existing  will  follow.  This  is  not  far 
distant. 

t  "  The  Coal  Fields  of  Great  Britain,"  pp.  447,  448.' 


THE    LIMITS    OF    OUR    COAL   SUPPLY.  225 

good  reason  to  believe  that  such  density  is  one  of  the  essential  con^ 
ditions  for  working  deep  coal.  Even  at  present  depths  of  working, 
density  and  hardness  of  the  accompanying  strata  is  one  of  the  most 
important  aids  to  easy  and  cheap  coal-getting.  With  a  dense  roof 
and  tioor  the  collier  works  vigorously  and  fearlessly,  and  he  escapes 
the  serious  cost  of  timbering. 

Those  who  have  never  been  underground,  and  only  read  of  colliery 
disasters,  commonly  regard  the  tire-damp  and  choke-damp  as  the 
collier's  most  deadly  enemies,  but  the  collier  himself  has  quite  as 
much  dread  of  a  rotten  roof  as  of  either  of  these  ;  he  knows  by  sad 
experience  how  much  bruising,  and  maiming,  and  crushing  of  human 
limbs  are  due  to  the  friability  of  the  rock  above  his  head.  Mr.  Hull 
quotes  the  case  of  the  Dunkinfield  colliery,  where,  at  a  depth  of 
about  2500  feet,  the  pressure  is  "  so  resistless  as  to  crush  in  circular 
arches  of  brick  four  feet  thick,"  and  to  snap  a  cast-iron  pillar  in 
twain  ;  but  he  does  not  give  any  account  of  the  density  of  the  accom- 
panying strata  at  the  place  of  these  occurrences.  I  suspect  that  it 
was  simply  a  want  of  density  that  allowed  the  superincumbent  pres- 
sure to  do  such  mischief.  The  circular  arches  of  brick  four  feet 
thick  were  but  poor  substitutes  for  a  roof  of  solid  rock  of  40  or  400 
feet  in  thickness  ;  an  arch  cut  in  such  a  rock  would  be  all  key-stone  : 
and  I  may  safely  venture  to  affirm  that  if,  in  the  deep  sinkings  of  the 
future,  we  do  encounter  the  increased  density  which  Mr.  Hull  antici- 
pates, this  will  be  altogether  advantageous.  I  fear,  however,  that  it 
will  not  be  so,  that  the  chief  difficulty  of  deep  coal-mining  will  arise 
from  occasional "  running  in"  due  to  deficient  density,  and  that  this 
difficulty  will  occur  in  about  the  same  proportion  of  cases  as  at  pres- 
ent,  but  will  operate  more  seriously  at  the  greater  depths. 

A  very  interesting  subject  for  investigation  is  hereby  suggested. 
Do  rocks  of  given  composition  and  formation  increase  in  density  as 
they  dip  downward  ;  and  if  so,  does  this  increase  of  density  follow 
any  law  by  which  we  may  determine  whether  their  power  of  resisting 
superincumbent  pressure  increases  in  any  approach  to  the  ratio  of 
the  increasing  pressure  to  which  they  are  naturally  subjected  ?  If 
the  increasing  density  and  power  of  resistance  peaches  or  exceeds 
this  ratio,  deep  mining  has  nothing  to  fear  from  pressure.  If  they 
fall  short  of  it,  the  difficulties  arising  from  pressure  may  be  serious. 
Friability,  viscosity,  and  power  of  resisting  a  crushing  strain  must  bo 
considered  in  reference  to  this  question. 

Mr.  Hull  has  collected  a  considerable  amount  of  data  bearing  upon 
the  rate  of  increase  of  temperature  with  depth.  His  conclusions 
give  a  greater  rate  of  increase  than  is  generally  stated  by  geologists  ; 
but  for  the  present  argument  I  will  accept  without  prejudice,  as  the 
lawyers  say,  his  basis  of  a  range  of  1°  F.  for  60  feet.  According  to 
this,  the  rocks  will  reach  99-6°,  a  little  above  blood  heat,  at  3000  feet, 
and  116-3°  at  the  supposed  limit  of  4000  feet.  It  is  assumed  by  Mr. 
Hull,  by  the  Commissioners,  and  most  other  authorities,  that  this 
rock  temperature  of  116°  will  limit  the  possibilities  of  coal-mining. 
At  the  average  prices  of  the  last  three  years,  or  the  prospective  prices 
of  the  next  three  years,  this  temperature  may  be,  like  difficulties  of  the 
thin  seams,  an  insurmountable  barrier  ;  but  I  contend  that  at  higher 
prices  we  may  work  coal  at  this,  and  even  far  higher,  rock  tempera- 
tures ;  that  it  matters  not  how  high  the  thermometer  rises  as  we  de- 
scend, we  shall  still  go  lower  and  still  get  coal  so  long  as  prices  rise 


SCIENCE    IK    SHOUT    CHAPTERS. 

with  tlie  mercury.  Given  this  condition,  and  I  have  no  doubt  that 
coal  may  be  worked  where  the  rock  temperature  shall  reach  or  even 
exceed  212°.  I  do  not  say  that  we  shall  actually  work  coal  at  such 
depths  ;  but  if  we  do  not,  the  reason  will  be,  not  that  the  thermome- 
ter is  too  high,  but  that  prices  are  too  low  ;  in  other  words,  value, 
not  temperature,  will  determine  the  working  limits. 

Mr.  Leifchild,  in  the  last  number  of  the  Edinburgh  Review,  in  dis- 
cussing this  question,  tells  iis  that  "  the  normal  heat  of  our  blood  is 
98°,  and  fever  heat  commences  at  100°,  and  the  extreme  limit  of  fever 
heat  may  be  taken  at  112°.  Dr.  Thudichum,  a  physician  who  has 
specially  investigated  this  subject,  has  concluded  fiom  experiments 
on  his  own  body  at  high  temperatures,  that  at  a  heat  of  140°  no  work 
whatever  could  be  carried  on,  and  that  at  a  temperature  of  from  130 J 
to  140°  only  a  very  small  amount  of  labor,  and  that  at  short  periods, 
was  practicable  ;  and  further,  that  human  labor  daily,  and  at  ordi- 
nary periods,  is  limited  by  100°  of  temperature,  as  a  iixed  point,  and 
then  the  air  must  be  dry,  for  in  moist  air  he  did  not  think  men  could 
endure  ordinary  labor  at  a  temperature  exceeding  90°." 

It  may  be  presumptuous  on  my  part  to  dispute  the  conclusions  of 
a  physician  on  such  a  subject,  but  I  do  so  nevertheless,  as  the  data 
required  are  simple  practical  facts  such  as  are  better  obtained  by 
furnace-working  than  by  sick-room  experience. 

During  the  hottest  days  of  the  summer  of  1868  I  was  engaged  in 
making  some  experiments  in  the  re-heating  furnaces  at  Sir  John 
Brown  and  Co.  's  works,  Sheffield,  and  carried  a  thermometer  about 
with  me  which  I  suspended  in  various  places  where  the  men  were 
working.  At  the  place  where  I  was  chiefly  engaged  (a  corner  between 
two  sets  of  furnaces),  the  thermometer,  suspended  in  a  position 
where  it  was  not  affected  by  direct  radiations  from  the  open  furnaces, 
stood  at  120°  while  the  furnace  doors  were  shut.  The  radiant  heat  to 
which  the  men  themselves  were  exposed  while  mkiang  their  greatest 
efforts  in  placing  and  removing  the  piles  was  far  higher  than  this, 
but  I  cannot  state  it,  not  having  placed  the  thermometer  in  the  posi- 
tion of  the  men.  In  one  of  the  Bessemer  pits  the  thermometer 
reached  140°,  and  men  worked  there  at  a  kind  of  labor  demanding 
great  muscular  effort.  It  is  true  that  during  this  same  week  the  pud- 
dlers  were  compelled  to  leave  their  work  ;  but  the  tremendous 
amount  of  concentrated  exertion  demanded  of  the  puddler  in  front 
of  a  furnace,  which,  during  the  time  of  removing  the  balls,  radiates  a 
degree  of  heat  quite  sufficient  to  roast  a  sirloin  of  beef,  if  placed  in 
the  position  of  the  puddler's  hands,  is  beyond  comparison  with  that 
which  would  be  demanded  of  a  collier  working  even  at  a  depth  giv- 
ing a  theoretical  rock  temperature  of  212°,  and  aided  by  the  coal-cut- 
ting and  other  machinery  that  sufficiently  high  prices  would  readily 
command.  In  some  of  the  operations  of  glass-making,  the  ordinary 
summer  working  temperature  is  considerably  above  100°,  and  the 
radiant  heat  to  which  the  workmen  are  subjected  far  exceeds  212°. 
This  is  the  case  during  a  "  pot  setting,"  and  in  the  ordinary  work  of 
flashing  crown  glass. 

As  regards  the  mere  endurance  of  a  high  temperature,  the  well- 
known  experiments  of  Blagden,  Sir  Joseph  Banks,  and  others  have 
shown  that  the  human  body  can  endure  for  short  periods  a  tempera- 
ture of  260°  F.,  and  upward.  My  own  experience  of  furnace-work, 
and  of  Turkish  baths,  quite  satisfies  me  that  I  could  do  a  fair  day's 


THE   LIMITS   OF   OUR   COAL   SUPPLY.  227 

work  of  six  or  eight  hours  in  a  temperature  of  130°  F.,  provided  I 
were  free  from  the  encumbrances  of  clothing,  and  had  access  to 
abundance  of  tepid  water.  This  in  a  still  atmosphere  ;  but  with  a 
moving  current  of  dry  air  capable  of  promoting  vigorous  evaporation 
from  the  skin,  I  suspect  that  the  temperature  might  be  ten  or  fifteen 
degrees  higher.  I  enjoy  ordinary  walking  exercise  in  a  well-ventilated 
Turkish  bath  at  150°,  and  can  endure  it  at  180°. 

In  order  to  obtain  further  information  on  this  point,  I  have  written 
to  Mr.  Tyndall,  the  proprietor  of  the  Turkish  baths  at  Newingtoii 
Butts.  He  is  an  architect,  who  has  had  considerable  experience  in 
the  employment  of  workmen  and  in  the  construction  of  Turkish 
baths  and  other  hot-air  chambers.  He  sa3Ts  :  "  Shampooers  work  in 
my  establishment  from  four  to  five  hours  at  a  time  in  a  moist  atmos- 
phere at  a  temperature  ranging  from  105°  to  110°.  I  have  myself 
worked  twenty  hours  out  of  twenty-four  in  one  day  in  a  temperature 
over  110°.  Once  for  ono  half-hour  I  shampooed  in  185°.  At  the 
enamel  works  in  Pimlico,  belonging  to  Mr.  Mackenzie,  men  work 
daily  in  a  heat  of  over  300°.  The  moment  a  man  working  in  a  110° 
heat  begins  to  drink  alcohol,  his  tongue  gets  parched,  and  he  is 
obliged  to  coninue  drinking  while  at  work,  and  the  brain  gets  so 
excited  that  he  cannot  do  half  the  amount.  I  painted  my  skylights, 
taking  me  about  four  hours,  at  a  temperature  of  about  145°  ;  also  the 
hottest  room  skylights,  which  took  me  one  hour,  coming  out  at  inter- 
vals for  "  a  cooler,"  at  a  temperature  of  180°.  I  may  add  in  conclu- 
sion, that  a  man  can  work  well  in  a  moist  temperature  of  110°  if  he 
perspires  freely." 

The  following,  by  a  writer  whose  testimony  may  be  safely  accept- 
ed, is  extracted  from  an  account  of  ordinary  passenger  ships  of  the 
Ked  Sea,  in  the  Illustrated  News,  of  November  9th,  1872  :  "  The  tern, 
perature  in  the  stoke-hole  was  145°.  The  floor  of  this  warm  region 
is  close  to  the  ship's  keel,  so  it  is  very  far  below.  There  are  twelve 
boilers,  six  on  each  side,  each  with  a  blazing  furnace,  which  has  to 
be  opened  at  regular  intervals  to  put  in  new  coals,  or  to  be  poked  up 
with  long  iron  rods.  This  is  the  duty  of  the  poor  wretches  who  are 
doomed  to  this  work.  It  is  hard  to  believe  that  human  beings  could 
be  got  to  labor  under  such  conditions,  yet  such  persons  are  to  be 
found.  The  work  of  stoking  or  feeding  the  fires  is  usually  done  by 
Arabs,  while  the  work  of  bringing  the  coal  from  the  bunkers  is  done 
by  sidi-wallahs  or  negroes.  At  times  some  of  the  more  intelligent  of 
these  are  promoted  to  the  stoking.  The  negroes  who  do  this  kind  of 
work  come  from  Zanzibar.  They  are  generally  short  men,  with 
strong  limbs,  round  bullet  heads,  and  the  very  best  of  good  nature  in 
their  dispositions.  •  Some  of  them  will  work  half  an  hour  in  such  P 
place  as  the  stoke-hole  without  a  drop  of  perspiration  on  their  dark 
skins.  Others,  particularly  the  Arabs,  when  it  is  so  hot  as  it  often  is 
in  the  Red  Sea,  have  to  be  carried  up  in  a  fainting  condition,  and  r»ro 
restored  to  animation  by  dashing  buckets  of  water  over  them  as  they 
lie  on  deck." 

It  must  be  remembered  that  the  theoretical  temperature  of  116°  nt 
4000  feet,  the  133°  at  5000  feet,  or  the  150°  at  6000  feet,  are  the  tem- 
peratures of  the  undisturbed  rock  ;  that  this  rock  is  a  bad  conductor  of 
heat,  whose  surface  may  be  considerably  cooled  by  radiation  and 
convection  ;  and  therefore  we  are  by  no  means  to  regard  the  rock 
temperature  as  that  of  the  air  of  the  roads  and  workings  of  the  deep 


228  SCIENCE   IX   SHORT   CHAPTERS. 

coal-pits  of  the  future.*  It  is  true  that  the  Royal  Commissioners 
have  collected  many  facts  showing  that  the  actual  difference  between 
the  face  of  the  rocks  of  certain  pits  and  the  air  passing  through  them 
is  but  small  ;  but  these  data  are  not  directly  applicable  to  the  ques- 
tion under  consideration  for  the  three  following  reasons  : 

First  The  comparisons  are  made  between  the  temperature  of  tho 
air  and  the  actual  temperature  of  the  opened  and  already-cooled 
strata,  while  the  question  to  be  solved  is  the  difference  between  the 
theoretical  temperature  of  the  unopened  earth  depths  and  that  of 
the  air  in  roads  and  workings  to  be  opened  through  them. 

Second.  The  cooling  effect  of  ventilation  must  (as  the  Commission- 
ers themselves  state)  increase  in  a  ratio  which  "  somewhat  exceeds 
the  ratio  of  the  difference  between  the  temperature  of  the  air  and 
that  of  the  surrounding  surface  with  which  it  is  in  contact."  Thus, 
the  lower  we  proceed  the  more  and  more  effectively  cooling  must  a 
given  amount  of  ventilation  become. 

The  third,  and  by  far  the  most  important,  reason  is,  that  in  the 
deep  mining  of  the  future,  special  means  will  be  devised  and  applied 
to  the  purpose  of  lowering  the  temperature  of  the  workings  ;  that,  as 
the  descending  efforts  of  the  collier  increase  with  the  ascending  value 
of  the  coal,  a  new  problem  will  be  offered  for  solution,  and  the 
method  of  working  coal  will  be  altered  accordingly.  In  the  cases 
quoted  by  the  Commissioners,  the  few  degrees  of  cooling  were 
effected  by  a  system  of  ventilation  that  was  devised  to  meet  the 
requirements  of  respiration,  and  not  for  the  purpose  of  cooling  the 
mine. 

It  would  be  very  presumptuous  for  any  one  in  1873  to  say  how  this 
special  cooling  will  actually  be  effected,'  but  I  will  nevertheless  vent- 
ure to  indicate  one  or  two  principles  which  may  be  applied  to  the 
solution  of  the  problem.  First  of  all,  it  must  be  noted  that  very 
deep  mines  are  usually 'dry  ;  and  there  is  good  reason  to  believe  that, 
before  reaching  the  Commissioners'  limit  of  4000  feet,  dry  mining 
would  be  the  common,  and  at  and  below  4000  feet  the  universal,  case. 
At  present  we  usually  obtain  coal  from  water-bearing  strata,  and  all 
our  arrangements  are  governed  by  this  very  serious  contingency. 
With  water  removed,  the  whole  system  of  coal-mining  maybe  revolu- 
tionized, and  thus  the  aspect  of  this  problem  of  cooling  the  workings 
would  become  totally  changed. 

Those  who  are  acquainted  with  the  present  practice  of  mining  are 
aware  that  when  an  estate  is  taken,  and  about  to  be  worked  for  coal, 
the  first  question  to  be  decided  is  the  dip  of  the  measures,  in  order 
that  the  sinking  may  be  made  "  on  the  deep"  of  the  whole  range. 
The  pits  are  not  sunk  at  that  part  of  the  range  where,  at  first  sight, 
the  coal  appears  the  most  accessible,  but,  on  the  contrary,  at  tho 
deepest  part.  It  is  then  carried  on  to  some  depth  belo\v  the  coal 
seam  which  is  to  be  worked,  in  order  to  form  a  "  surnpf  "  or  recepta* 
cle  from  which  the  water  may  be  wound  or  pumped.  The  necessity 
for  this  in  water-bearing  strata  is  obvious  enough.  If  the  collier  be* 

*  In  a  paper  on  the  Comstock  Mines,  read  at  the  Pittsburg  meeting  of  the 
American  Institute  of  Mining  Engineers  in  1879,  by  Mr.  John  A.  Church,  the  hot 
mine  waters  are  described  as  reaching  158°  Fahr.  (?o  hot  that  men  have  been  scalded 
to  death  by  falling  into  them).  The  highest  recorded  air  temperature  there  is  128°. 
These  are  silver  mines,  and  vigorously  worked  in  spite  of  this  temperature  and 
great  humidity.  A  much  higher  temperature  is  endurable  in  dry  air. 


THE   LIMITS   OF   OUR   COAL   SUPPLY.  229 

gan  at  the  shallowest  portion  of  his  range,  and  attempted  to  proceed 
downward,  he  would  be  "  drowned  out  "  unless  he  worked  as  a  coal- 
diver  rather  than  a  coal-ininer.  By  sinking  in  the  deep  he  works 
upward,  away  from  the  water,  which  all  drains  down  to. the  sumpf, 
from  which  it  is  pumped. 

The  modern  practice  is  to  sink  "  a  pair  of  pits,"  both  on  the  deep, 
and  v/ithin  a  short  distance  of  each  other.  The  object  of  the  second 
is  ventilation.  By  contrivances,  which  I  need  not  here  detail,  the 
air  is  made  to  descend  one  of  the  pits,  "  the  downcast  shaft,"  then 
to  traverse  the  roads  and  workings  wherein  ventilation  is  required, 
and  return  by  a  reverse  route  to  "the  upcast  shaft,"  by  which  it 
ascends  to  the  surface. 

Thus  it  will  be  seen  that,  whenever  the  temperature  of  the  roads 
and  workings  exceeds  that  of  the  outer  atmosphere,  the  air  currents 
have  to  be  forced  to  travel  through  the  mine  in  a  direction  contrary 
to  their  natural  course.  The  cooler  air  of  the  downcast  shaft  has  to 
climb  the  inclined  roads,  and  then  after  attaining  its  maximum  tem- 
perature in  the  fresh  workings  must  descend  the  roads  till  it  reaches 
the  upcast  shaft.  The  cool  air  must  rise  and  the  warmer  air  descend. 

What,  then,  would  be  the  course  of  the  mining  engineer  when  all 
the  existing  difficulties  presented  by  water-bearing  strata  should  be 
removed,  and  their  place  taken  by  a  new  and  totally  different  obsta- 
cle, viz.  high  temperature  ?  Obviously  to  reverse  the  present  mode 
of  working — to  sink  on  the  upper  part  of  the  range  and  drive  down- 
ward.  In  such  a  system  of  working  the  ventilation  of  the  pit  will  be 
most  powerfully  aided  or  altogether  effected  by  natural  atmospheric 
currents.  An  upcast  once  determined  by  artificial  means,  it  will 
thereafter  proceed  spontaneously,  as  the  cold  air  of  the  downcast 
shaft  will  travel  by  a  descending  road  to  the  workings,  and  then 
after  becoming  heated  will  simply  obey  the  superior  pressure  of  the 
heavy  column  behind,  and  proceed  by  an  upward  road  to  the  upcast 
shaft.  As  the  impelling  force  of  the  air  current  will  be  the  difference 
between  the  weight  of  the  cool  column  of  air  in  the  downcast  shaft 
and  roads  and  the  warm  column  in  the  upcast,  the  available  force  of 
natural  ventilation  and  cooling  will  increase  just  as  demanded,  i.e.  it 
will  increase  with  the  depth  of  the  workings  and  the  heat  of  the 
rocks.  A  mining  engineer  who  knows  what  is  actually  done  with 
present  arrangements,  will  see  at  once  that  with  the  above-stated 
advantages  a  gale  of  wind  or  even  a  hurricane  might  be  directed 
through  any  particular  roads  or  long-wall  workings  that  were  once 
opened.  Let  us  suppose  the  depth  to  be  5000  feet,  the  rock  temper- 
ature at  starting  133°,  and  that  of  the  outer  air  60°,  we  should  have  a 
torrent  of  air  73°  cooler  than  the  rocks  rushing  furiously  downward, 
then  past  the  faco  of  the  heated  strata,  and  absorbing  its  heat  to  such 
an  extent  that  the  upcast  shaft  would  pour  forth  a  perpetual  blast  of 
hot  air  like  a  gigantic  furnace  chimney. 

But  this  is  not  all  ;  the  heat  and  dryness  of  these  deep  workings  of 
the  future  place  at  our  disposal  another  and  still  more  efficient  cool- 
ing agency  than  even  that  of  a  hurricane  of  dry-air  ventilation.  In 
the  first  part  of  the  sinking  of  the  deep  shafts  the  usual  water-bear- 
ing strata  would  be  encountered,  and  the  ordinary  means  of  "  tub- 
bing" or  "  coffering"  would  probably  be  adopted  for  temporary  con- 
venience during  sinking.  Doorways,  however,  would  be  left  in  the 
tubbing  at  suitable  places  for  tapping  at  pleasure  the  wettest  and 


230  SCIENCE   IK   SHORT   CHAPTERS. 

most  porous  of  the  strata.  Streams  of  cold  water  could  thus  be 
poured  down  the  sides  of  the  shaft,  which,  on  reaching  the  bottom, 
would  flow  by  a  downhill  road  into  the  workings.  The  stream  of  air 
rushing  by  the  same  route  and  becoming  heated  in  its  course  would 
powerfully  assist  the  evaporation  of  the  water.  The  deeper  and 
hotter  the  pit,  the  more  powerful  would  be  these  cooling  agencies. 

As  the  specific  heat  of  water  is  about  five  times  that  of  the  coal- 
measure  rocks,  or  the  coal  itself,  every  degree  of  heat  communicated 
to  each  pound  of  water  would  abstract  one  degree  from  five  pounds 
of  rock.  But  in  the  conversion  of  water  at  60°  into  vapor  at  say 
100°,  the  amount  of  heat  absorbed  is  equivalent  to  that  required  to 
raise  the  same  weight  of  water  about  1000°,  and  thus  the  effective 
cooling  power  on  the  rock  would  be  equivalent  to  5000°. 

The  workings  once  opened  (I  assume  as  a  matter  of  course  that  by 
this  time  pillar-and-stall  working  will  be  entirely  abandoned  for  long- 
wall  or  something  better),  there  would  be  no  difficulty  in  thus  pour- 
ing streams  of  water  and  torrents  of  air  through  the  workings  during 
the  night,  or  at  any  suitable  time  preparatory  to  the  operations  of 
the  miner,  who  long  before  the  era  of  such  deep  workings  will  be 
merely  the  director  of  coal  cutting  and  loading  machinery. 

Given  a  sufficiently  high  price  for  coal  at  the  pit's  mouth  to  pay 
wages  and  supply  the  necessary  fixed  capital,  I  see  no  insuperable 
difficulty,  so  far  as  mere  temperature  is  concerned,  in  working  coal  at 
double  the  depth  of  the  Eoyal  Commissioners'  limit  of  possibility. 
At  such  a  depth  of  8000  feet  the  theoretical  rock-temperature  is  183°. 

By  the  means  above  indicated,  I  have  no  doubt  that  this  could  be 
reduced  to  an  air  temperature  below  110° — that  at  which  Mr.  Tyn- 
dall's  shampooers  ordinarily  work.  Of  course  the  newly-exposed 
face  of  the  coal  would  have  its  initial  temperature  of  183°  ;  but  this 
is  a  trivial  heat  compared  to  the  red-hot  radiant  surfaces  to  which 
puddlers,  shinglers,  glassmakers,  etc.  are  commonly  exposed. 
Divested  of  the  incumbrance  of  clothing,  with  the  whole  surface  of 
the  skin  continuously  fanned  by  a  powerful  stream  of  air— which, 
during  working  hours  need  be  but  partly  saturated  with  vapor — a 
sturdy  midland  or  north-countryman  would  work  merrily  enough  at 
short  hours  and  high  wages,  even  though  the  newly-exposed  face  of 
coal  reached  212°  ;  for  we  must  remember  that  this  new  coal-face 
would  only  correspond  to  the  incomparably  hotter  furnace-doors  and 
fires  of  the  steamship  stoke-holes. 

The  high  temperature  at  8000  or  even  10,000  feet  would  present  a 
really  serious  difficulty  during  the  first  opening  of  communication 
between  the  two  pits.  A  spurt  of  brave  effort  would  here  be  neces- 
sary, and  if  anybody  doubts  whether  Englishmen  could  be  found  to 
make  the  effort,  let  him  witness  a  "pot-setting"  at  a  glass-house.  ^ 
Negro  labor  might  be  obtained  if  required,  but  my  experience  among 
English  workmen  leads  me  to  believe  that  they  will  never  allow 
negroes  or  any  others  to  beat  them  at  home  in  any  kind  of  work 
where  the  wages  paid  are  proportionate  to  the  effort  demanded. 

If  I  am  right  in  the  above  estimates  of  working  possibilities,  our 
coal  resources  may  be  increased  by  about  forty  thousand  millions  of 
tons  beyond  the  estimate  of  the  Commissioners.  To  obtain  such  an 
additional  quantity  will  certainly  be  worth  an  effort,  and  unless  we 
suffer  a  far  worse  calamity  than  the  loss  of  all  our  minerals— viz.  a 
deterioration  of  British  energy— the  effort  will  assuredly  be  made.  . 


THE   LIMITS   OF   OUR   COAL   SUPPLY.  231 


I  have  said  repeatedly  that  it  is  not  physical  difficulties  but  market 
value  that  will  determine  the  limits  of  our  coal-mining.  This,  like 
all  other  values,  is  of  course  determined  by  the  relation  between  de- 
mand and  supply.  Fuel  being  one  of  the  absolute  necessaries  of  life, 
the  demand  for  it  must  continue  so  long  as  the  conditions  of  human 
existence  remain  as  at  present,  and  the  outer  limits  of  the  possible 
value  of  coal  will  be  determined  by  that  of  the  next  cheapest  kind  of 
fuel  which  is  capable  of  superseding  it. 

We  begin  by  working  the  best  and  most  accessible  seams,  and 
while  those  remain  in  abundance  the  average  value  of  coal  will  be  de- 
termined by  the  cost  of  producing  it  under  these  easy  conditions. 
Directly  these  most  accessible  seams  cease  to  supply  the  whole  de- 
mand, the  market  value  rises  until  it  becomes  sufficient  to  cover  the 
cost  of  working  the  less  accessible  ;  and  the  average  value  will  be 
regulated  not  by  the  cost  of  working  what  remains  of  the  first  or  easy 
mines,  but  by  that  of  working  the  most  difficult  that  must  be  worked 
in  order  to  meet  the  demand.  This  is  a  simple  case  falling  under 
the  well-established  economic  law,  that  the  natural  or  cost  value  of 
any  commodity  is  determined  by  the  cost  value  of  the  most  costly 
portion  of  it.  Thus,  the  only  condition  under  which  we  can  proceed 
to  sink  deeper  and  deeper,  is  a  demand  of  sufficient  energy  to  keep 
pace  with  the  continually  increasing  cost  of  production.  This  con- 
dition can  only  be  fulfilled  when  there  is  no  competing  source  of 
cheaper  production  which  is  adequate  to  supply  the  demand. 

The  question  then  resolves  itself  into  this.  Is  any  source  of  sup- 
ply likely  to  intervene  that  will  prevent  the  value  of  coal  from  rising 
sufficiently  to  cover  the  cost  of  working  the  coal  seams  of  4000  feet 
and  greater  depth  ?  Without  entering  upon  the  question  of  peat  and 
wood  fuel,  both  of  which  will  for  some  uses  undoubtedly  come  into 
competition  with  British  coal  as  it  rises  in  value,  I  believe  that  there 
are  sound  reasons  for  concluding  that  our  London  fireplaces,  and 
those  of  other  towns  situated  on  the  sea-coast  and  the  banks  of  navi- 
gable rivers,  will  be  supplied  with  transatlantic  coal  long  before  we 
reach  the  Commissioners'  limit  of  4000  feet.  The  highest  prices  of 
last  winter,  if  steadily  maintained,  would  be  sufficient  to  bring  about 
this  important  change.  Temporary  upward  jerks  of  the  price  of 
coal  have  very  little  immediate  effect  upon  supply,  as  the  surveying, 
conveyance,  boring,  sinking,  and  fully  opening  of  a  new  coal  estate 
is  a  work  of  some  years. 

The  Royal  Commissioners  estimate  that  the  North  American  coal- 
fields contain  an  untouched  coal  area  equal  to  seventy  times  the 
whole  of  ours.  Further  investigation  is  likely  to  increase  rather  than 
diminish  this  estimate.  An  important  portion  of  this  vast  source  of 
supply  is  well  situated  for  shipment,  and  may  be  easily  worked  at 
little  cost.  Hitherto,  the  American  coal  fields  have  been  greatly 
neglected,  partly  on  account  of  the  temptations  to  agricultural  occu- 
pation which  are  afforded  "by  the  vast  area  of  the  American  continent, 
and  partly  by  the  barbarous  barriers  of  American  politics.  Large 
amounts  of  capital  which,  under  the  social  operation  of  the  laws  of 
natural  selection,  would  have  been  devoted  to  the  unfolding  of  the 
vast  mineral  resources  of  the  United  States,  are  still  wastefully  in- 
vested in  the  maintenance  of  protectively  nursed  and  sickly  imita- 
tions of  English  manufactures.  When  the  political  civilization  of 
the  United  States  becomes  sufficiently  advanced  to  establish  a 


232  SCIENCE   IN   SHORT   CHAPTERS. 

national  free-trade  policy,  this  perverted  capital  will  flow  into  its  natu- 
ral channels,  and  the  citizens  of  the  States  will  be  supplied  with  the 
more  highly  elaborated  industrial  products  at  a  cheaper  rate  than  at 
present,  by  obtaining  them  in  exchange  for  their  superabundant  raw 
material  from  those  European  countries  where  population  is  over- 
flowing the  raw  material  supplies. 

When  this  time  arrives,  and  it  may  come  with  the  characteristic 
suddenness  of  American  changes,  the  question  of  American  versus 
English  coal  in  the  English  markets  will  reduce  itself  to  one  of  hori- 
zontal versus  vertical  difficulties.  If  at  some  future  period  the  aver- 
age depth  of  the  Newcastle  coal-pits  becomes  3000  feet  greater  than 
those  of  the  pits  near  the  coast  of  the  Atlantic  or  American  lakes, 
and  if  the  horizontal  difficulties  of  3000  miles  of  distance  are  less 
than  the  vertical  difficulties  of  3000  feet  of  depth,  then  coals  will  be 
carried  from  America  to  Newcastle.  They  will  reach  London  and  the 
towns  on  the  South  Coast  before  this — that  is,  when  the  vertical  diffi- 
culties at  Newcastle  plus  those  of  horizontal  traction  from  Newcastle 
to  the  south,  exceed  those  of  eastward  traction  across  the  Atlantic. 

As  the  cost  of  carriage  increases  in  a  far  smaller  ratio  than  the 
open  ocean  distance,  there  is  good  reason  for  concluding  that  the  day 
when  London  houses  will  be  warmed  by  American  coal  is  not  very 
far  distant.  We,  in  England,  who  have  outgrown  the  pernicious 
folly  of  "  protecting  native  industry,"  will  heartily  welcome  so  desir- 
able a  consummation.  It  will  render  unnecessary  any  further  in- 
quiry into  the  existence  of  London  "  coal  rings"  or  combinations  for 
restricted  output  among  colliers  or  their  employers.  If  any  morbid 
impediments  to  the  free  action  of  the  coal  trade  do  exist,  the  stimu- 
lating and  purgative  influence  of  foreign  competition  will  rapidly 
restore  the  trade  to  a  healthy  condition. 

The  effect  of  such  introduction  of  American  coal  will  not  be  to  per- 
petually lock  up  our  deep  coal,  nor  even  to  stop  our  gradual  progress 
toward  it.  We  shall  merely  proceed  downward  at  a  much  slower 
rate,  for  in  America,  as  with  ourselves,  the  easily  accessible  coal  will 
be  first  worked,  and  as  that  becomes  exhausted,  the  deeper,  more 
remote,  thinner,  and  inferior  will  only  remain  to  be  worked  at  con- 
tinually increasing  cost.  When  both  our  own  and  foreign  coal  cost 
more  than  peat,  or  wood,  or  other  fuel,  then  and  therefore  will  coal 
become  quite  inaccessible  to  us,  and  this  will  probably  be  the  case 
long  before  we  are  stopped  by  the  physical  obstacles  of  depth,  den- 
sity, or  high  temperature. 

As  this  rise  of  value  must  of  necessity  be  gradual,  and  as  the  super- 
seding of  British  by  foreign  coal,  as  well  as  the  final  disuse  of  coal, 
will  gradually  converge  from  the  circumference  toward  the  centres  of 
supply,  from  places  distant  from  coal-pits  to  those  close  around 
them,  we  shall  have  ample  warning  and  opportunity  for  preparing 
for  the  social  changes  that  the  loss  of  the  raw  material  will  enforce. 

The  above-quoted  writer,  in  the  Edinburgh  Review,  expresses  in 
strong  and  unqualified  terms  an  idea  that  is  very  prevalent  in  Eng- 
land and  abroad  :  he  says  that  "  The  course  of  manufacturing  su- 
premacy of  wealth  and  power  is  directed  by  coal.  That  wonderful 
mineral,  of  the  possession  of  which  Englishmen  have  thought  so 
little,  but  wasted  so  much,  is  the  modern  realization  of  the  philoso- 
pher's stone.  This  chemical  result  of  primeval  vegetation  has  been 
the  means  by  its  abundance  of  raising  this  country  to  an  unprece- 


THE   LIMITS   OF   OUR   COAL   SUPPLY.  233 

dented  height  of  prosperity,  and  its  deficiency  might  have  the  effect 
of  lowering  it  to  slow  decline." 

*  *  "It  raises  up  one  people  and  casts  down  another  ;  it  makes 
railways  on  land  and  paths  on  the  sea.  It  founds  cities,  it  rules 
nations,  it  changes  the  course  of  empires."  *-" 

The  fallacy  of  these  customary  attributions  of  social  potency  to 
mere  mineral  matter  is  amply  shown  by  facts  that  are  previously 
stated  by  the  reviewer  himself.  He  tells  us  that  "  the  coal-fields  of 
China  extend  over  an  area  of  400,000  square  miles  ;  and  a  good  geol- 
ogist, Baron  von  Kichthofen,  has  reported  that  he  himself  has  found 
a  coal-field  in  the  province  of  Hunau  covering  an  area  of  21,700 
square  miles,  which  is  nearly  double  our  British  coal  area  of  12,000 
square  miles.  In  the  province  of  Shansi,  the  Baron  discovered 
nearly  30,000  square  miles  of  coal,  with  unrivalled  facilities  for  min- 
ing. But  all  these  vast  coal-fields,  capable  of  supplying  the  whole 
world  for  some  thousands  of  years  to  come,  are  lying  unworked." 

If  "  the  course  of  manufacturing  supremacy  of  wealth  and  of 
power"  were  directed  by  coal,  then  China,  which  possesses  33-3  times 
more  of  this  directive  force  than  Great  Britain,  and  had  so  early  a 
start  in  life,  should  be  the  supreme  summit  of  the  industrial  world. 
If  this  solid  hydrocarbon  "  raises  up  one  people  and  casts  down  an- 
other," the  Chinaman  should  be  raised  thirty-three  times  and  three 
tenths  higher  than  the  Englishman  ;  if  it  "  makes  railways  on  land 
and  paths  on  the  sea,"  the  Chinese  railways  should  be  33-3  times 
longer  than  ours,  and  the  tonnage  of  their  mercantile  marine  33-3 
times  greater. 

Every  addition  to  our  knowledge  of  the  mineral  resources  of  other 
parts  of  the  world  carries  us  nearer  and  nearer  to  the  conclusion  that 
the  old  idea  of  the  superlative  abundance  of  the  natural  mineral 
resources  of  England  is  a  delusion.  We  are  gradually  discovering 
that,  with  the  one  exception  of  tin-stone,  we  have  but  little  if  any 
more  than  an  average  supply  of  useful  ores  and  mineral  fuel.  It  is  a 
curious  fact,  and  one  upon  which  we  may  profitably  ponder,  that  the 
poorest  and  the  worst  iron  'ores  that  have  ever  been  commercially 
reduced,  are  those  of  South  Staffordshire  and  the  Cleveland  district, 
and  these  are  the  two  greatest  iron-making  centres  of  the  world. 
There  are  no  ores  of  copper,  zinc,  tin,  nickel,  or  silver  in  the  neigh- 
borhood of  Birmingham,  nor  any  golden  sands  upon  the  banks  of  the 
Bea,  yet  this  town  is  the  hardware  metropolis  of  the  world,  the 
fatherland  of  gilding  and  plating,  and  is  rapidly  becoming  supreme 
in  the  highest  art  of  gold  and  silver  work. 

These,  and  a  multitude  of  other  analogous  facts,  abundantly  refute 
the  idea  that  the  native  minerals,  the  natural  fertility,  tne  navigable 
rivers,  or  the  convenient  seaports,  determine  the  industrial  and  com- 
mercial supremacy  of  nations.  The  moral  forces  exerted  by  the  indi- 
vidual human  molecules  are  the  true  components  which  determine 
the  resulting  force  and  direction  of  national  progress.  It  is  the  in- 
dustry and  skill  of  our  workmen,  the  self-denial,  the  enterprise,  and 
organizing  ability  of  our  capitalists,  that  has  brought  our  coal  so 
precociously  to  the  surface  and  redirected  for  human  advantage  the 
buried  energies  of  ancient  sunbeams,  while  the  fossil  fuel  of  other 
lands  has  remained  inert. 

The  foreigner  who  would  see  a  sample  of  the  source  of  British 
prosperity  must  not  seek  for  it  in  a  geological  museum  or  among  our 


234  SCIENCE   IN    SHORT    CHAPTERS. 

subterranean  rocks  ;  let  him  rather  stand  on  the  Surrey  side  of  Lon- 
don Bridge  from  8  to  10  A.M.  and  contemplate  the  march  of  one  of 
the  battalions  of  our  metropolitan  industrial  army,  as  it  pours  forth 
in  an  unceasing  stream  from  the  railway  stations  toward  the  city. 
]tn  analysis  of  the  moral  forces  which  produce  the  earnest  faces  and 
rapid  steps  of  these  rank  and  file  and  officers  of  commerce  will  reveal 
the  ftfue  elements  of  British  greatness,  rather  than  any  laboratory 
dissection  of  our  coal  or  ironstone. 

Fuel  and  steam-power  have  been  urgently  required  by  all  mankind. 
Englishmen  supplied  these  wants.  Their  urgency  was  primary  and 
they  were  first  supplied,  even  though  the  bowels  of  the  earth  had  to 
be  penetrated  in  order  to  obtain  tliem.  In  the  present  exceptional 
and  precocious  degree  of  exhaustion  of  our  coal  treasures,  we  have 
the  effect  not  the  cause  of  British  industrial  success. 

If  in  a  ruder  age  our  greater  industrial  energy  enabled  us  to  take 
the  lead  in  supplying  the  ruder  demands  of  our  fellow-creatures,  why 
should  not  a  higher  culture  of  those  same  abundant  energies  qualify 
us  to  maintain  our  position,  and  enable  us  to  minister  to  the  more 
refined  and  elaborate  wants  of  a  higher  civilization  ?  There  are  other 
necessary  occupations  quite  as  desirable  as  coal-digging,  furnace- 
feeding,  and  cotton-spinning. 

The  approaching  exhaustion  of  our  coal  supplies  should  therefore 
serve  us  as  a  warning  for  preparation.  Britain  will  be  forced  to 
retire  from  the  coal  trade,  and  should  accordingly  prepare  her  sons 
for  higher  branches  of  business,  for  those  in  which  scientific  knowl- 
edge and  artistic  training  will  rep]ace  mere  muscular  strength  and 
mechanical  skill.  We  have  attained  our  present  material  prosperity 
mainly  by  our  excellence  in  the  use  of  steam-power  ;  let  us  now 
struggle  for  supremacy  in  the  practical  application  of  brain-power. 

We  have  time  and  opportunity  for  this.  The  exhaustion  of  our 
coal  supplies  will  go  on  at  a  continually  retarding  pace— we  shall 
always  be  approaching  the  end,  but  shall  never  absolutely  reach  it, 
as  every  step  of  approximation  will  diminish  the  rate  of  approach  ; 
like  the  everlasting  process  of  reaching  a  given  point  by  continually 
halving  our  distance  from  it. 

First  of  all  we  shall  cease  to  export  coal  ;  then  we  shall  throw  up  the 
most  voracious  of  our  coal-consuming  industries,  such  as  the  reduc- 
tion of  iron-ore  in  the  blast-furnace  ;  then  copper-smelting  and  the 
manufacture  of  malleable  iron  and  steel  from  the  pig,  and  so  on  pro- 
gressively. If  we  keep  in  view  the  natural  course  and  order  of  such 
progress,  and  intelligently  prepare  for  it,  the  loss  of  our  coal  need 
not  in  the  smallest  degree  retard  the  progress  of  our  national  pros- 
perity. 

If,  however,  we  act  upon  the  belief  that  the  advancement  of  a* 
nation  depends  upon  the  mere  accident  of  physical  advantages,  if  we 
fold  our  arms  and  wrait  for  Providence  to  supply  us  with  a  physical 
substitute  for  coal,  we  shall  become  Chinamen,  minus  the  unworked 
coal  of  China. 

If  our  educational  efforts  are  conducted  after  the  Chinese  model  ? 
if  we  stultify  the  vigor  and  freshness  of  young  brains  by  the  weary, 
dull,  and  useless  cramming  of  words  and  phrases  ;  if  we  poison  and 
pervert  the  growing  intellect  of  British  youth  by  feeding  it  upon  the 
decayed  carcasses  of  dead  languages,  and  on  effete  and  musty  litera- 
ture, our  progress  will  be  proportionally  Chinaward  ;  but  if  we  shake 


"THE  ENGLISHMAN'S  FIRESIDE/'  235 

off  that  monkish  inheritance  which  leads  so  many  of  us  blindly  lo 
believe  that  the  business  of  education  is  to  produce  scholars  rather 
than  men,  and  direct  our  educational  efforts  toward  the  requirements 
of  the  future  rather  than  by  the  traditions  of  the  past,  we  need  have 
no  fear  that  Great  Britain  will  decline  with  the  exhaustion  of  her 
coal-fields. 

The  teaching  and  training  in  schools  and  colleges  must  be  directly 
and  designedly  preparatory  to  those  of  the  workshop,  the  warehouse, 
and  the  office  ;  for  if  our  progress  is  to  be  worthy  of  our  beginning, 
the  moral  and  intellectual  dignity  of  industry  must  be  formally 
acknowledged  and  systematically  sustained  and  advanced.  Hitherto, 
we  have  been  the  first  and  the  foremost  in  utilizing  the  fossil  forces 
which  the  miner  has  unearthed  ;  hereafter  we  must  in  like  manner 
avail  ourselves  of  the  living  forces  the  philosopher  has  revealed. 
Science  must  become  as  familiar  among  all  classes  of  Englishmen  as 
their  houshold  fuel.  The  youth  of  England  must  be  trained  to 
observe,  generalize,  and  investigate  the  phenomena  and  forces  of  the 
world  outside  themselves  ;  and  also  those  moral  forces  within  them- 
selves, upon  the  right  or  wrong  government  of  which  the  success  or 
failure,  the  happiness  or  misery  of  their  lives  will  depend. 

With  such  teaching  and  training  the  future  generations  of  England 
will  make  the  best  and  most  economical  use  of  their  coal  while  it 
lasts,  and  will  still  advance  in  material  and  moral  prosperity  in  spite 
of  its  progressive  exhaustion. 


CHAPTER  XXVIII. 

"  THE  ENGLISHMAN'S  FIRESIDE.'' 

DURING  the  investment  of  Paris,  the  Comptes  Eendus  of  the  Acad- 
emy of  Sciences  were  mainly  filled  with  papers  on  the  construction 
and  guidance  of  balloons  ;  with  the  results  of  ingenious  researches 
on  methods  of  making  milk  and  butter  without  the  aid  of  cows  ;  on 
the  extraction  of  nutritious  food  from  old  boots,  saddles,  and  other 
organic  refuse  ;  and  other  devices  for  rendering  the  general  famine 
more  endurable.  In  like  manner,  our  present  coal  famine  is  direct- 
ing an  important  amount  of  scientific,  as  well  as  commercial,  atten 
tion  to  the  subject  of  economizing  coal  and  finding  substitutes  for  it. 

A  few  thoughtful  men  have  shocked  their  fellow-sufferers  very  out. 
rageously  by  wishing  that  coal  may  reach  £3  per  ton,  and  remain  at 
that  price  for  a  year  or  two.  I  confess  that,  in  spite  of  my  own 
empty  coal-cellar  and  small  income,  I  am  one  of  those  hard-hearted 
cool  calculators,  being  confident  that,  even  from  the  narrow  point  of 
view  of  my  own  outlay  in  fuel,  the  additional  amount  I  should  thus 
pay  in  the  mean  time  would  be  a  good  investment,  affording  an  ample 
return  in  the  saving  due  to  consequent  future  cheapness. 

Regarded  from  a  national  point  of  view,  I  am  convinced  that  £3  a 
ton  in  London,  and  corresponding  prices  in  other  districts,  if  thus 
maintained,  would  be  an  immense  national  blessing.  I  say  this, 
baing  convinced  that  nothing  short  of  pecuniary  pains  and  penalties 


£36  SCIENCE   IN   SHORT   CHAPTERS. 

of  ruinous  severity  will  stir  the  blind  prejudices  of  Englishmen,  and 
force  them  to  desist  from  their  present  stupid  and  sinful  waste  of  the 
greatest  mineral  treasure  of  the  island. 

One  of  the  grossest  of  our  national  manifestations  of  conservative 
stupidity  is  our  senseless  idolatrous  worship  of  that  domestic  fetich, 
"  the  Englishman's  fireside."  We  sacrifice  health,  we  sacrifice  com- 
fort, we  begrime  our  towns  and  all  they  contain  with  sooty  foulness, 
we  expend  an  amount  far  exceeding  the  interest  of  the  national  debt, 
and  discount  our  future  prospects  of  national  prosperity,  in  order 
that  we  may  do  what  ?  Enjoy  the  favorite  recreation  of  idiots.  It  is 
a  well-known  physiological  fact  that  an  absolute  idiot,  with  a  cranium 
measuring  sixteen  inches  in  circumference,  will  sit  and  stare  at  a 
blazing  fire  for  hours  and  hours  continuously,  all  the  day  long,  except 
when  feeding,  and  that  this  propensity  varies  with  the  degree  of 
mental  vacuity. 

Few  sights  are  more  melancholy  than  the  contemplation  of  a  party 
of  English  fire- worshippers  seated  in  a  semicircle  round  the  family 
fetich  on  a  keen  frosty  day.  They  huddle  together,  roast  their 
knees,  and  grill  their  faces,  in  order  to  escape  the  chilling  blast  that 
is  brought  in  from  all  the  chinks  of  leaky  doors  and  windows  by  the 
very  agent  they  employ,  at  so  much  cost,  for  the  purpose  of  keeping 
the  cold  away.  The  bigger  the  fire,  the  greater  the  draught,  the  hot- 
ter their  faces  the  colder  their  backs,  the  greater  the  consumption  of 
coal  the  more  abundant  the  crop  of  chilblains,  rheumatism,  catarrh, 
and  other  well-deserved  miseries. 

The  most  ridiculous  element  of  such  an  exhibition  is  the  compla- 
cent self-delusion  of  the  victims.  They  believe  that  their  idol  be- 
stows upon  them  an  amount  of  comfort  unknown  to  other  people, 
that  it  affords  the  most  perfect  and  salubrious  ventilation,  and,  above 
all,  that  it  is  a  "  cheerful  "  institution.  The  "  cheerfulness"  is, 
perhaps,  the  broadest  part  of  the  whole  caricature,  especially  when 
we  consider  that,  according  to  this  theory  of  the  cheerfulness  of  fire- 
gazing,  the  16-inch  idiot  must  be  the  most  cheerful  of  all  human 
beings. 

The  notion  that  our  common  fireplaces  and  chimneys  afford  an 
efficient  means  of  ventilation  is  almost  too  absurd  for  serious  dis- 
cussion. Everybody  who  has  thought  at  all  on  the  subject  is  aware 
that  in  cold  weather  the  exhalations  of  the  skin  and  lungs,  the  prod- 
ucts of  gas-burning,  etc.,  are  so  much  heated  when  given  off  that 
they  rise  to  the  upper  part  of  the  room  (especially  if  any  cold  outer 
air  is  admitted),  and  should  be  removed  from  there  before  they  cool 
again  and  descend.  Now,  our  fireplace  openings  are  just  where  they 
ought  not  to  be  for  ventilation  ;  they  are  at  the  lower  part  of  the  . 
room,  and  thus  their  action  consists  in  creating  a  current  of  cold  air 
or  "  draught"  from  doors  and  windows,  which  cold  current  at  once 
descends,  and  then  runs  along  the  floor,  chilling  our  toes  and  pro- 
voking chilblains. 

This  cold  fresh  air,  having  done  its  worst  in  the  way  of  making  us 
uncomfortable,  passes  directly  up  the  chimney  without  doing  us  any 
service  for  purposes  of  respiration.  Our  mouths  are  usually  above 
the  level  of  the  chimney  opening,  and  thus  we  only  breathe  the  viti- 
ated atmosphere  which* it  fails  to  remove. 

Not  only  does  the  fire-opening  fail  to  purify  the  air  we  breathe,  it 
actually  prevents  the  leakage  of  the  upper  part  of  the  windows  and 


doors  from  assisting  in  the  removal  of  the  upper  stratum  of  vitiated 
air,  for  the  strong  up-draught  of  the  chimney  causes  these  openings 
to  be  fully  occupied  by  an  inflowing  current  ot  cold  air,  which  at 
once  descends,  and  then  proceeds,  as  before  stated,  to  the  chimney. 
If  the  leakage  is  insufficient  to  supply  the  necessary  amount  of  chil- 
blain-making and  bronchitis-producing  draught,  it  has  to  enter  by 
way  of  the  chimney-pot  in  the  form  of  occasional  spasms  of  down- 
draught,  accompanied  by  gusts  of  choking  and  blackening  smoke.  It 
is  a  fact  not  generally  known,  that  smoky  chimneys  are  especial 
English  institutions,  one  of  the  peculiar  manifestations  of  our  very 
superior  domestic  comfortableness. 

It  is  true  that,  in  some  of  our  rooms,  an  Arnott's  ventilator  opens 
into  the  upper  part  of  the  chimney,  but  this  was  intended  by  Dr. 
Arnott  as  an  adjunct  to  his  modification  of  the  German  stove,  and 
such  ventilator  can  only  act  efficiently  where  a  stove  is  used.  The 
pressure  required  to  fairly  open  it  can  only  be  regularly  obtained 
when  the  chimney  is  closed  below,  or  its  lower  opening  is  limited  to 
that  of  a  stove-pipe. 

The  mention  of  a  German  stove  has  upon  an  English  fire-worship- 
per a  similar  effect  to  the  sight  of  water  upon  a  mad  dog.  Again  and 
again,  when  I  have  spoken  of  the  necessity  of  reforming  our  fire- 
places, the  first  reply  elicited  has  been,  "  What,  would  you  have  ns 
use  German  stoves  ?"  In  every  case  where  I  have  inquired  of  the 
exclaimer,  "  Y/hat  sort  of  thing  is  a  German  stove  ?"  the  answer  has 
proved  that  the  exclamation  was  but  a  manifestation  of  blind  preju- 
dice based  upon  total  ignorance.  These  people  who  are  so  much 
shocked  at  the  notion  of  introducing  "  German  stoves"  have  no  idea 
of  the  construction  of  the  stoves  which  deservedly  bear  this  title. 
Their  notion  of  a  German  stove  is  one  of  those  wretched  iron  boxes 
of  purely  English  invention  known  to  ironmongers  as  "  shop  stoves. ' ' 
These  things  get  red  hot,  their  red-hot  surface  frizzles  the  dust  parti- 
cles that  float  in  the  atmosphere  and  perfume  the  apartment  accord- 
ingly. This,  however  disagreeable,  is  not  very  mischievous,  perhaps 
the  reverse,  as  many  of  these  dust  particles,  which  are  revealed  by  a 
sunbeam,  are  composed  of  organic  matter  which,  as  Dr.  Tyndall 
argues,  may  be  carriers  of  infection.  If  we  must  inhale  such  things, 
it  is  better  that  we  should  breathe  them  cooked  than  take  them  raw. 

The  true  cause  of  the  headaches  and  other  mischief  which  such 
stoves  unquestionably  induce  is  very  little  understood  in  this  coun- 
try. It  has  been  falsely  attributed  to  over-drying  of  the  atmosphere, 
and  accordingly  evaporating  pans  and  other  contrivances  have  been 
attached  to  such  stoves,  but  with  little  or  no  advantage.  Other  ex- 
planations are  given,  but  the  true  one  is  that  iron  when  red  hot  is  per- 
meable by  carbonic  oxide.  This  was  proved  by  the  researches  of  Pro- 
fessor Graham,  who  showed  that  this  gas  not  only  can  pass  through 
red-hot  iron  with  singular  facility,  but  actually  does  so  whenever 
there  is  atmospheric  air  on  one  side  and  cabonic  oxide  on  the  other. 

For  the  benefit  of  my  non-chemical  readers,  I  may  explain  that 
when  any  of  our  ordinary  fuel  is  burned  there  are  two  products  of 
carbon  combustion,  one  the  result  of  complete  combustion,  the  other 
of  semi-combustion — carbonic  acid  and  carbonic  oxide — the  former, 
though  suffocating  when  breathed  alone  or  in  large  proportion,  is 
not  otherwise  poisonous,  and  has  no  disagreeable  odor  ;  it  is  in  fact 
rather  agreeable  in  small  quantities,  being  the  material  of  champagne 


238  SCIENCE   IN   SHOUT   CHAPTERS. 

bubbles  and  of  those  of  other  effervescing  drinks.  Carbonic  oxide, 
the  product  of  semi-combustion,  is  quite  different.  Breathed  only 
in  small  quantities,  it  acts  as  a  direct  poison,  producing  peculiarly 
oppressive  headaches.  Besides  this,  it  has  a  disagreeable  odor.  It 
thus  resembles  many  other  products,  of  imperfect  combustion,  such 
as  those  which  are  familiar  to  everybody  who  has  ever  blown  out  a 
tallow  candle  and  left  the  red  wick  to  its  own  devices. 

On  this  account  alone  any  kind  of  iron  stove  capable  of  becom- 
ing red- hot  should  be  utterly  condemned.  If  Englishmen  did  their 
travelling  in  North  Europe  in  the  winter,  their  self-conceit  respecting 
the  comfort  of  English  houses  would  be  cruelly  lacerated,  and  none 
such  would  perpetrate  the  absurdity  of  applying  the  name  of  "  Ger- 
man stove"  to  the  iron  fire-pots  that  are  sold  as  stoves  by  English 
ironmongers. 

As  the  Germans  use  so  great  a  variety  of  stoves,  it  scarcely  cor- 
rect to  apply  the  title  of  German  to  any  kind  of  stove,  unless  we 
limit  ourselves  to  North  Germany.  There,  and  in  Sweden,  Denmark, 
Norway,  and  Russia,  the  construction  of  stoves  becomes  a  speciality. 
The  Russian  stove  is  perhaps  the  most  instructive  to  us,  as  it  affords 
the  greatest  contrast  to  our  barbarous  device  of  a  hole  in  the  wall 
into  which  fuel  is  shovelled,  and  allowed  to  expend  nine  tenths  of  its 
energies  in  heating  the  clouds  while  only  the  residual  ten  per  cent, 
does  anything  toward  warming  the  room.  With  the  thermometer 
outside  below  zero,  a  house  in  Moscow  or  St.  Petersburg  is  kept  in- 
comparably more  warm  and  comfortable,  and  is  better  ventilated 
(though,  perhaps,  not  so  much  ventilated)  than  a  corresponding  class 
of  house  in  England,  where  the  outside  temperature  is  20  or  30 
degrees  higher,  and  this  with  the  consumption  of  about  one  fourth  of 
the  fuel  which  is  required  for  the  production  of  British  bronchitis. 

This  is  done  by,  first  of  all,  sacrificing  the  idiotic  recreation  of  fire- 
gazing,  then  by  admitting  no  air  into  the  chimney  but  that  which  is 
used  for  the  combustion  of  the  fuel  ;  thirdly,  by  sending  as  little  as 
possible  of  the  heat  up  the  chimney  ;  fourthly,  by  storing  the  heat 
obtained  from  the  fuel  in  a  suitable  reservoir,  and  then  allowing  it 
gradually  and  steadily  to  radiate  into  the  apartment  from  a  large  but 
not  overheated  surface. 

The  Russian  stove  by  which  these  conditions  are  fulfilled  is 
usually  an  ornamental,  often  a  highly  artistic,  handsome  article  of 
furniture,  made  of  fire-resisting  porcelain,  glazed  and  otherwise  dec- 
orated outside.  Internally  it  is  divided  by  thick  fire-clay  walls  into 
several  upright  chambers  or  flues,  usually  six.  Some  dry  firewood  is 
lighted  in  a  suitable  fireplace,  and  is  supplied  with  only  sufficient  air 
to  effect  combustion,  all  of  which  enters  below  and  passes  fairly 
through  the  fuel.  The  products  of  combustion  being  thus  undiluted 
with  unnecessary  cold  air,  are  very  highly  heated,  and  in  this  state 
pass  up  compartment  or  flue  No.  1  ;  they  are  then  deflected,  and  pass 
down  No.  2  ;  then  up  No.  3,  then  down  No.  4,  then  up  No.  5,  then 
down  No.  6.  At  the  end  of  this  long  journey  they  have  given  up 
most  of  their  heat  to  the  24  heat-absorbing  surfaces  of  the  fire-clay 
walls  of  the  six  flues. 

When  the  interior  of  the  stove  is  thus  sufficiently  heated,  the  fire- 
door  and  the  communication  with  the  chimney  are  closed,  and  the 
fire  is  at  once  extinguished,  having  now  done  its  day's  work  ;  the 
interior  of  the  stove  has  bottled  up  its  calorific  force,  and  holds  it 


"THE  ENGLISHMAN'S  FIRESIDE.''  239 

ready  for  emission  into  the  apartment.  This  is  effected  by  the  nat-. 
ural  properties  of  the  walls  of  the  earthenware  reservoir.  They  are 
bad  conductors  and  good  radiators.  The  heat  slowly  passes  through 
to  the  outside  of  the  stove,  is  radiated  into  the  apartment  from  a 
large  and  moderately  heated  surface,  which  affords  a  genial  and  well- 
diffused  temperature  throughout. 

There  is  no  scorching  in  one  little  red-hot  hole,  or  corner,  or  box, 
and  freezing  in  the  other  parts  of  the  room.  There  are  no  draughts, 
as  the  chimney  is  quite  closed  as  soon  as  the  heat  reservoir  is  sup- 
plied. If  one  of  these  heat  reservoirs  is  placed  in  the  hall,  where  it 
may  form  a  noble  ornament  and  can  easily  communicate  with  an 
underground  flue,  it  warms  every  part  of  the  house,  and  enables  the 
Bussian  to  enjoy  a  luxurious  temperate  climate  indoors  in  spite  of 
•arctic  winter  outside. 

In  a  house  thus  warmed  and  free  from  draughts  or  blasts  of  cold 
air,  ventilation  becomes  the  simplest  of  problems.  Nothing  more  is 
required  than  to  provide  an  inlet  and  outlet  in  suitable  places,  and 
of  suitable  dimensions,  when  the  difference  between  the  specific 
gravity  of  the  cold  air  without  and  warm  air  within  does  all  the  rest. 
Nothing  is  easier  to  arrange  than  to  cause  all  the  entering  air  to  be 
warmed  on  its  way  by  the  hall  stove,  and  to  regulate  the  supply 
which  each  apartment  shall  receive  from  this  general  or  main  stream 
by  adjusting  its  own  upper  outlet.  In  our  English  houses,  with 
open  chimneys,  all  such  systematic,  scientific  ventilation  is  impossi- 
ble, on  account  of  the  dominating,  interfering,  useless,  and  comfort- 
destroying  currents  produced  by  these  wasteful  air-shafts. 

I  should  add  that  the  Russian  porcelain  reservoirs  may  be  con- 
structed for  a  heat  supply  of  a  few  hours  or  for  a  whole  day,  an  d  I 
need  say  nothing  further  in  refutation  of  the  common  British  preju- 
dice which  confounds  so  admirable  and  truly  scientific  a  contrivance 
with  the  iron  fire-pot  above  referred  to. 

There  is  another  kind  of  stove,  which,  for  the  sake  of  distinction, 
I  may  call  Scandinavian,  as  it  is  commonly  used  in  Norway,  Sweden, 
and  Denmark,  besides  some  parts  of  North  Germany.  This  is  a  tall, 
hollow  iron  pillar,  of  rectangular  section,  varying  from  three  to  six 
feet  in  width,  and  rising  half-way  to  the  ceiling  of  the  room,  and 
sometimes  higher.  A  fire  is  lighted  at  the  lower  part,  and  the  prod- 
ucts of  combustion,  in  their  way  upward,  meet  with  horizontal  iron 
plates,  which  deflect  them  first  to  the  right,  then  to  the  left,  and 
thus  compel  them  to  make  a  long  serpentine  journey  before  they 
reach  the  chimney.  By  this  means  they  give  off  their  heat  to  the 
large  surface  of  iron  plate,  and  enter  the  chimney  at  a  comparatively 
low  temperature.  The  heat  is  radiated  into  the  apartment  from  the 
large  metal  surface,  no  part  of  which  approaches  a  red  heat.  A  fur- 
ther economy  is  commonly  effected  by  placing  this  iron  pillar  in  the 
wall  separating  two  rooms,  so  that  one  of  its  faces  is  in  each  room. 
Thus  two  rooms  are  heated  by  one  fire.  One  of  these  may  be  the 
kitchen,  and  the  same  fire  that  prepares  the  food  may  be  used  to 
warm  the  dining-room.  The  fire-worshipper  is  of  course  deprived  of 
his  "  cheerful  "  occupation  of  staring  at  the  coals,  and  he  also  loses 
his  playthings,  as  neither  poker,  tongs,  nor  coal-scuttle  are  included 
in  the 'furniture  of  an  apartment  thus  heated.  People  differently 
constituted  consider  that  an  escape  from  the  dust,  dirt,  and  clatter  of 
these  is  a  decided  advantage. 


240  SCIENCE   IX   SHORT   CHAPTERS. 

Of  course  these  stoves  of  our  northern  neighbors  are  costly — may 
be  very  costly  when  highly  ornamental.  The  stove  of  a  Norwegian 
"bonder,"  or  peasant  proprietor,  costs  nearly  half  as  much  as  the 
two-roomed  wooden  house  in  which  it  is  erected,  but  the  saving  it 
effects  renders  it  a  good  investment.  It  would  cost  £100  or  £200  to 
fit  up  an  English  mansion  with  suitable  porcelain  stoves  of  the  Rus- 
sian pattern,  but  a  saving  of  £20  a  year  in  fuel  would  yield  a  good 
return  as  regards  mere  cost,  while  the  gain  in  comfort  and  healthful- 
ness  would  be  so  great  that,  once  enjoyed  and  understood,  such  out- 
lay would  be  willingly  made  by  all  who  could  afford  it,  even  if  no 
money  saving  were  effected. 

;  r  Only  last  week  I  was  discussing  this  question  in  a  railway  carriage, 
where  one  of  my  fellow-passengers  was  an  intelligent  Holsteiner.  He 
confirmed  the  heresy  by  which  I  had  shocked  the  others,  in  exulting 
in  the  high  price  of  coal,  and  wishing  it  to  continue.  He  told  us 
that  when  wood  was  abundant  in  his  country,  fuel  was  used  as  bar- 
barously, as  wastefully,  and  as  inefficiently  as  it  now  is  here,  but 
that  the  deforesting  of  the  land,  and  the  great  cost  of  fuel,  forced 
upon  them  a  radical  reform,  the  result  of  which  is  that  they  now 
have  their  houses  better  warmed,  and  at  a  less  cost  than  when  fuel 
was  obtainable  at  one  fourth  of  its  present  cost. 

Such  will  be  the  case  with  us  also  if  we  can  but  maintain  the  pres- 
ent coal  famine  during  one  or  two  more  winters,  especially  if  we 
should  have  the  further  advantage  of  some  very  severe  weather  in  the 
mean  time.  Hence  the  cruel  wishes  above  expressed.  The  coal 
famine  would  scarcely  be  necessary  if  we  had  Russian  winters,  for  in 
such  case  our  houses,  instead  of  being  as  they  are,  merely  the  most 
uncomfortable  in  North  Europe,  would  be  quite  uninhabitable. 
With  our  mild  winters  we  reqiiire  the  utmost  severity  of  fuel  prices 
to  civilize  our  warming  and  ventilating  devices. 


CHAPTEK    XXIX. 
"BATLY'S  BEADS." 

To  the  Editor  of  the  Times. 

SIB,- — The  curious  breaking  up  of  the  thin  annular  rim  of  the  sun 
which  is  uncovered  just  before  and  just  after  totality,  or  which  sur- 
rounds the  moon  during  an  annular  eclipse,  has  been  but  occasion- 
ally observed,  and  some  scepticism  as  to  the  accuracy  of  Baily's 
observations  has  lately  arisen.  Having  attempted  an  explanation  of 
the  "  beads,"  I  have  looked  with  much  interest  for  the  reports  of  the 
eclipse  of  1870,  for,  if  I  am  right,  they  ought  to  have  been  well  seen 
on  this  occasion.  This  has  been  the  case.  We  are  informed  that 
both  Lord  Lindsay  and  the  Eev.  S.  J.  Perry  have  observed  them,  and 
that  Lord  Lindsay  has  set  aside  all  doubts  respecting  their  reality  by 
securing  a  photographic  record  of  their  appearance. 

My  explanation  is  that  they  are  simply  sun-spots  seen  in  profile- 
spots  just  caught  in  the  fact  of  turning  the  sun's  edge.  All  observers 
are  now  agreed  as  to  the  soundness  of  Galileo's  original  description 


"BAILY'S  BEADS."  241 

of  the  spots — that  they  are  huge  cavities,  great  rifts  of  the  luminous 
surface  of  the  sun,  many  thousands  of  miles  in  diameter,  and  proba- 
bly some  thousand  miles  deep.  Let  us  suppose  the  case  of  a  spot — 
say  2000  miles  deep  and  10,000  miles  across  (Sir  W.  Herschel  has 
measured  spots  of  50,000  miles  diameter).  When  such  a  spot  in  the 
course  of  the  sun's  rotation  reaches  that  part  which  forms  the  visible 
edge  of  the  sun,  it  must,  if  rendered  visible,  be  seen  as  a  notch  ;  but 
what  will  be  the  depth  of  such  a  notch  ?  Only  about  1 -430th  of  the 
sun's  diameter.  But  the  apparent  depth  would  be  much  less  as  the 
edge  or  riin  of  the  spot  next  to  the  observer  would  cut  off  more  or  less 
of  its  actually  visible  depth,  this  amount  depending  upon  the  lateral 
or  east  and  west  diameter  of  the  spot  and  its  position  at  the  time  of 
observation. 

Thus,  the  visible  depth  of  such  a  notch  would  rarely  exceed  one 
thousandth  of  the  sun's  apparent  diameter,  or  might  be  much  less. 
The  sun  being  globular,  the  edge  which  is  visible  to  us  is  but  our 
horizon  of  his  fiery  ocean,  which  we  see  athwart  the  intervening  stir- 
face  as  it  gradually  bends  away  from  our  view.  So  small  an  indent 
upon  this  edge  would,  under  ordinary  circumstances  of  observation, 
be  rendered  quite  invisible  by  the  irradiation  of  the  vast  globular 
surface  of  the  glaring  photosphere,  upon  which  it  would  visually 
encroach. 

If,  however,  this  body  of  glare  could  be  screened  off,  and  only  a 
line  of  the  sun's  edge,  less  than  one  thousandth  of  his  diameter,  re- 
main visible,  the  notch  would  appear  as  a  distinct  break  in  this 
curved  line  of  light.  If  a  group  of  spots,  or  a  great  irregular  spot 
with  several  umbrae,  were  at  such  a  time  situated  upon  the  sun's 
edge,  the  appearance  of  a  series  of  such  notches  or  breaks  leaving 
intermediate  detachments  of  the  visible  ring  of  the  photosphere 
would  be  the  necessary  result,  and  thus  would  be  presented  exactly 
the  appearance  described  as  "  Baily's  beads." 

I  have  been  led  to  anticipate  a  display  of  these  beads  during  the 
late  eclipse  by  the  fact  that  some  days  preceding  it  a  fine  group  of 
spots— visible  to  the  naked  eye  through  a  London  fog— were  travel- 
ling toward  the  eastern  edge  of  the  sun,  and  should  have  reached  the 
limb  at  about  the  time  of  the  eclipse.  The  beads  were  observed  by 
the  Rev.  S.  J.  Perry  just  where  I  expected  them  to  appear.  I  have 
not  yet  learned  on  which  side  of  the  sun  they  were  observed  and 
photographed  by  Lord  Lindsay. 

Baily's  first  observation  of  the  beads  was  made  during  the  annular 
eclipse  of  May  15,  1836.  That  year,  like  1870,  was  remarkable  for  a 
great  display  of  sun-spots.  As  in  1870,  they  were  then  visible  to  the 
naked  eye.  I  well  remember  my  own  boyish  excitement  when,  a  few 
weeks  before  the  eclipse  of  1836,  I  discovered  a  spot  upon  the  red- 
dened face  of  the  setting  sun — a  thing  I  had  read  about,  and  sup- 
posed that  only  great  astronomers  were  privileged  to  see.  The  rich- 
ness of  this  sun-spot  period  is  strongly  impressed  on  my  memory  by 
the  fact  that  I  continued  painfully  watching  the  dazzling  sun, 
literally  "  watching  and  weeping,"  up  to  the  Sunday  of  the  eclipse, 
on  which  day  also  I  saw  a  large  spot  through  my  bit  of  smoked  glass. 

The  previous  records  of  these  appearances  of  fracture  of  the  thin 
line  of  light  are  those  of  Halley,  in  his  memoir  on  the  total  eclipse  of 
1715,  and  Maclauren's  on  that  of  1737.  Both  of  these  correspond  to 
great  spot  periods  ;  the  intervals  between  1715,  1737,  1836,  and  187G 


242  SCIENCE   IN   SHORT   CHAPTERS. 

are  all  divisible  by  eleven.     The  observed  period  of  sun-spot  occur- 
rence is  eleven  years  and  a  small  fraction. 

I  am  anxiously  awaiting  the  arrival  of  Lord  Lindsay's  long- 
exposure  photographs  of  the  corona,  for  if  they  represent  the  varying 
degrees  of  splendor  of  this  solar  appendage,  the  explanations  ot- 
fered  in  Chapter  xii.  of  my  essay  on  "  The  1'uel  of  the  Sun"  will  be 
very  severely  tested  by  them.  Yours  respectfully, 

W.  MATTIEU  WTLTTAMS. 
Woodside  Green,  Croydou,  January  4, 1871. 


CHAPTER  XXX. 

THE   COLOEING   OF   GKEEN   TEA. 

THE  following  is  a  copy  of  my  report  to  the  Grocer  on  a  sample  of 
the  ingredients  actually  used  by  the  Chinese  for  coloring  of  tea, 
which  sample  was  sent  to  the  Grocer  office  by  a  reliable  correspondent 
at  Shanghai  (November,  1873).  I  reprint  it  because  the  subject  has 
a  general  interest  and  is  commonly  misunderstood  : 

"  I  have  examined  the  blue  and  the  yellowish-white  powders 
received  from  the  office,  and  find  that  the  blue  is  not  indigo,  as  your 
Shanghai  correspondent  very  naturally  supposes,  but  is  an  ordinary 
commercial  sample  of  Prussian  blue.  It  is  not  so  bright  as  some  of 
our  English  samples,  and  by  mere  casual  observation  may  easily  be 
mistaken  for  indigo.  Prussian  blue  is  a  well-known  compound  of 
iron,  cyanogen,  and  potassium.  Commercial  samples  usually  con- 
tain a  little  clayey  or  other  earthy  impurities,  which  is  the  case  with 
this  Chinese  sample.  There  are  two  kinds  of  Prussian  blue — the 
insoluble,  and  the  basic  or  soluble.  The  Chinese  sample  is  insoluble. 

"  This  is  important,  seeing  that  we  do  not  eat  our  tea-leaves,  but 
merely  drink  an  infusion  of  them  ;  and  thus  even  the  very  small 
quantity  which  faces  the  tea-leaf  remains  with  the  spent  leaves,  and 
is  not  swallowed  by  the  tea-drinker,  who  therefore  need  have  no  fear 
of  being  poisoned  by  this  ornamental  adulterant. 

"  Its  insolubility  is  obvious,  from  the  fact  that  green  tea  does  not 
give  a  blue  infusion,  which  would  be  the  case  if  the  Prussian  blue 
were  dissolved. 

"  There  are  some  curious  facts  bearing  on  this  subject  and  connect- 
ed with  the  history  of  the  manufacture  of  Prussian  blue.  Messrs. 
Bramwell,  of  Newcastle-on-Tyne,  who  may  be  called  the  fathers  of 
this  branch  of  industry,  established  their  works  about  a  century  ago. 
It  was  first  sold  at  two  guineas  per  Ib. ;  in  1815  it  had  fallen  to  10s. 
6d,  in  1820  to  2s.  6cZ.,  then  down  to  Is.  9d  in  1850.  I  see  by  the 
Price  Current  of  the  Oil  Trade  Review  that  the  price  has  recently  been 
somewhat  higher. 

"  In  the  early  days  of  the  trade  a  large  portion  of  Messrs.  Bramwell's 
produce  was  exported  to  China.  The  Chinese  then  appear  to  have 
been  the  best  customers  of  the  British  manufacturers  of  this  article. 
Presently,  however,  the  Chinese  demand  entirely  ceased,  and  it  was 
discovered  that  a  common  Chinese  sailor,  who  had  learned  some- 


THE   COLORING   OF   GREEN   TEA.  243 

thing  of  the  importation  of  this  pigment  to  his  native  country,  came 
to  England  in  an  East  Indiaman,  visited,  or  more  probably  obtained 
employment  at  a  Prussian  blue  manufactory,  learned  the  process, 
and,  on  his  return  to  China,  started  there  a  manufactory  of  his  own, 
which  was  so  successful  that  in  a  short  time  the  whole  of  the  Chinese 
demand  was  supplied  by  native  manufacture  ;  and  thus  ended  our 
export  trade.  Those  who  think  the  Chinese  are  an  unteachable  and 
unimprovable  people  may  reflect  on  this  little  history. 

"  The  yellowish  powder  is  precisely  what  your  Shanghai  corre- 
spondent supposes.  It  is  steatite,  or  '  soapstone. '  This  name  is  very 
deceptive,  and,  coupled  with  the  greasy  or  unctuous  feel  of  the  sub- 
stance, naturally  leads  to  the  supposition  that  it  is  really,  as  it 
appears,  an  oleaginous  substance.  This,  however,  is  not  the  case. 
It  is  a  compound  of  silicia,  magnesia,  and  water,  with  which  are 
sometimes  associated  a  little  clay  and  oxide  of  iron.  Like  most 
magnesian  minerals,  it  has  a  curiously  smooth  or  slippery  surface, 
and  hence  its  name.  It  nearly  resembles  meerschaum,  the  smooth- 
ness of  which  all  smokers  understand. 

"  When  soapstone  is  powdered  and  rubbed  over  a  moderately  rough 
surface,  it  adheres,  and  forms  a  shining  film  ;  just  as  another  unctu- 
ous mineral,  graphite  (the  '  black  lead  '  of  the  housemaid),  covers 
and  polishes  ironwork.  On  this  account,  soapstone  is  used  in  some 
lubricating  compounds,  for  giving  the  finishing  polish  to  enamelled 
card,  and  for  other  similar  purposes. 

"  With  a  statement  of  these  properties  before  us,  and  the  interest- 
ing description  of  the  process  by  your  Shanghai  correspondent,  the 
whole  riddle  of  green-tea  coloring  and  facing  is  solved.  The  Prus- 
sian blue  and  soapstone  being  mixed"  together  when  dry  in  the  man- 
ner described,  the  soapstone  adheres  to  the  surface  of  the  particles  of 
blue,  and  imparts  to  them  not  only  a  pale  greenish  color,  but  also  its 
own  unctuous,  adhesive,  and  polishing  properties.  The  mixture 
being  well  stirred  in  with  the  tea-leaves,  covers  them  with  this 
facing,  and  thus  gives  both  the  color  and  peculiar  pearly  lustre  char- 
acteristic of  some  kinds  of  green  tea.  I  should  add  that  the  soap- 
stone,  like  the  other  ingredient,  is  insoluble,  and  therefore  perfectly 
harmless. 

"  Considering  the  object  to  be  attained,  it  is  evident  from  the  above 
that  John  Chinaman  understands  his  business,  and  needs  no  lessons 
from  European  chemists.  It  would  puzzle  ail  the  Fellows  of  the 
Chemical  Society,  though  they  combined  their  efforts  for  the  pur- 
pose, to  devise  a  more  effective,  cheap,  simple,  and  harmless  method 
of  satisfying  the  foolish  demand  for  unnaturally  colored  tea-leaves. 

"  When  the  tea-drinking  public  are  sufficiently  intelligent  to  prefer 
naturally  colored  leaves  to  the  ornamental  stuff  they  now  select,  Mr. 
Chinaman  will  assuredly  be  glad  enough  to  discontinue  the  addition 
of  the  Prussian  blue,  which  costs  him  so  much  more  per  Ib.  than  his 
tea-leaves,  and  will  save  him  the  trouble  of  the  painting  and  varnish- 
ing now  in  demand. 

In  the  mean  time  it  is  satisfactory  to  know  that,  although  a  few 
silly  people  may  be  deceived,  nobody  is  poisoned  by  this  practice  of 
coloring  green  tea.  I  say  '  a  few  silly  people, '  for  there  can  be  only 
a  few,  and  those  very  silly  indeed,  who  judge  of  their  tea  by  its 
appearance  rather  than  by  the  quality  of  the  infusion  it  produces. 

"  With  these  facts  before  us  it  is  not  difficult  to  trace  the  origin  of 


SCIENCE   IN   SHORT   CHAPTERS. 

the  oft-repeated  and  contradicted  statement  that  copper  is  used  in 
coloring  green  tea.  One  of  the  essential  ingredients  in  the  manufact- 
ure of  Prussian  blue  is  sulphate  of  iron,  the  common  commercial 
name  of  which  is  '  green  copperas.'  It  is  often  supposed  to  con- 
tain copper,  but  this  is  not  the  case. 

"  Your  Shanghai  correspondent  overrates  the  market  value  of  soap- 
stone  when  he  supposes  that  Chinese  wax  may  be  used  as  a  cheap 
substitute.  In  many  places — as,  for  instance,  the  '  Lizard  '  district 
of  Cornwall— great  veins  of  this  mineral  occur,  which,  if  needed, 
might  be  quarried  in  vast  abundance,  and  at  very  little  cost  on 
account  of  its  softness.  The  romantic  scenery  of  Kynance  Cove,  its 
caverns,  its  natural  arches,  the  '  Devil's  Bellows,'  the  '  Devil's 
Post-Office,'  the  'Devil's  Cauldrons,'  and  other  fantastic  forma- 
tions of  this  part  of  the  coast,  attributed  to  his  Satanic  Majesty  or 
the  Druids,  are  the  natural  results  of  the  waves  beating  away  the 
veins  of  soft  soapstone,  and  leaving  the  deformed  skeleton  rocks  of 
harder  serpentine  behind. ' ' 


CHAPTER  XXXI. 

•'IKON  FILINGS"  IN  TEA. 

1  HAVE  watched  the  progress  of  the  tea  controversy  and  the  other 
public  performances  of  the  public  analysts  with  considerable  inter- 
est ;  it  might  have  been  with  amusement,  but  for  the  melancholy 
degradation  of  chemical  science  which  they  involve. 

Among  the  absurdities  and  exaggerations  which  for  some  years 
past  have  been  so  industriously  trumpeted  forth  by  the  pseudo- 
chemists  who  trade  upon  the  adulteration  panic  and  consequent  de- 
mand for  chemical  certificates  of  purity,  the  continually  repeated 
statements  concerning  the  use  of  iron  filings  as  a  fraudulent  adulter- 
ant of  tea  takes  a'  prominent  place.  I  need  scarcely  remark  that,  in 
order  to  form  such  an  adulterant,  the  quantity  added  must  be  suffi- 
ciently great  to  render  its  addition  commercially  profitable  to  an 
extent  commensurate  with  the  trouble  involved. 

The  gentlemen  who,  since  the  passing  of  the  Adulteration  Act, 
have  by  some  kind  of  inspiration  suddenly  become  full-blown  chem- 
ists, have  certified  to  wilful  adulteration  of  tea  with  iron  filings,  and 
have  obtained  convictions  en  such  certificates,  when,  according  to 
their  own  statement,  the  quantity  contained  has  not  exceeded  5  per 
cent,  in  the  cheapest  qualities  of  tea.  Now,  the  price  of  such  tea  to 
the  Chinaman  tea-grower,  who  is  supposed  to  add  these  iron  filings, 
is  about  fourpence  to  sixpence  per  pound  ;  and  we  are  asked  to  be- 
lieve that  he  will  fraudulently  deteriorate  the  market  value  of  his 
commodity  for  the  sake  of  this  additional  l-20th  of  weight.  Suppos- 
ing that  he  could  obtain  his  iron  filings  at  twopence  per  pound,  his 
total  gain  would  thus  be  about  l-10th  of  a  penny  per  pound.  But 
can  he  obtain  such  iron  filings  in  the  quantity  required  at  such  a 
price  ?  A  little  reflection  on  a  few  figures  will  render  it  evident  that 
he  cannot,  and  that  such  adulteration  is  utterly  impossible. 


IN   TEA.  245 

I  find,  by  reference  to  the  Grocer  of  November  8th,  that  the  total 
deliveries  of  tea  into  the  port  of  London  during  the  first  ten  months 
of  1872  were  142,429,337  Ibs.,  and  during  the  corresponding  period  of 
1873,  139,092,409  Ibs.  Of  this  about  Si  millions  of  pounds  in  1873, 
and  10  millions  of  pounds  in  1872,  were  green,  the  rest  black.  This 
gives  in  round  numbers  about  160  millions  of  pounds  of  black  tea 
per  annum,  of  which  above  140  millions  come  from  China.  As  the 
Russians  are  greater  tea-drinkers  than  ourselves--  the  Americans  and 
British  colonists  are  at  least  equally  addicted  to  the  beverage,  and 
other  nations  consume  some  quantity — the  total  exports  from  China 
may  be  safely  estimated  to  reach  400  or  500  millions  of  pounds. 

Let  us  take  the  smaller  figure,  and  suppose  that  only  one  fourth  of 
this  is  adulterated,  to  the  extent  of  5  per  cent.,  with  iron  filings. 
How  much  would  be  required?  Just  five  millions  of  pounds  per 
annum. 

It  must  be  remembered  that  coarse  filings  could  not  possibly  be 
nsed  ;  they  would  show  themselves  at  once  to  the  naked  eye  as  rusty 
lumps,  and  would  shake  down  to  the  bottom  of  the  chest  ;  neither 
could  borings,  nor  turnings,  nor  plane-shavings  be  used.  Nothing 
but  fine  filings  would  answer  the  supposed  purpose.  I  venture  to 
assert  that  if  the  China  tea-growers  were  to  put  the  whole  world 
under  contribution  for  their  supposed  supply  of  fine  iron  filings,  this 
quantity  could  not  be  obtained. 

Let  anyone  who  doubts  this  borrow  a  blacksmith's  vise,  a  fine  file, 
and  a  piece  of  soft  iron,  then  take  off  his  coat  and  try  how  much  labor 
will  be  required  to  produce  a  single  ounce  of  filings,  and  also  bear  in 
mind  that  fine  files  are  but  very  little  used  in  the  manufacture  of 
iron.  As  the  price  of  a  commodity  rises  when  the  demand  exceeds 
the  supply,  the  Chinaman  would  have  to  pay  far  more  for  his  adulter- 
ant than  for  the  leaves  to  be  adulterated.  As  Chinese  tea-growers 
are  not  public  analysts,  we  have  no  right  to  suppose  that  they  would 
perpetrate  any  such  foolishness. 

The  investigations  reently  made  by  Mr.  Alfred  Bird,  of  Birming- 
ham, show  that  the  iron  found  in  tea-leaves  is  not  in  the  metallic 
state,  but  in  the  condition  of  oxide,  and  he  confirms  the  conclusions 
of  Zoller,  quoted  by  Mr.  J.  A.  Wanklyn  in  the  Chemical  News  of  Octo- 
ber 10th — viz.  that  compounds  of  iron  naturally  exist  in  genuine 
tea.  It  appears,  however,  that  the  ash  of  many  samples  of  black  tea 
contains  more  iron  than  naturally  belongs  to  the  plant  ;  and,  accept- 
ing Mr.  Bird's  statement,  that  this  exists  in  the  leaf  as  oxide  mixed 
with  small  silicious  and  micaceous  particles,  I  think  we  may  find  a 
reasonable  explanation  of  its  presence  without  adopting  the  puerile 
theory  of  the  adulteration  maniac,  who,  in  his  endeavor  to  prove  that 
everybody  who  buys  or  sells  anything  is  a  swindler,  has  at  once 
assumed  the  impossible  addition  of  iron  filings  as  a  makeweight. 

In  the  first  place  we  must  remember  that  the  commodity  in  de- 
mand is  black  tea,  and  that  ordinary  leaves  dried  in  an  ordinary 
manner  are  not  black,  but  brown.  Tea-leaves,  however,  contain  a 
large  quantity  of  tannin,  a  portion  of  which  is,  when  heated  in  the 
leaves,  rapidly  convertible  into  gallo-tannic  or  tannic  acid.  Thus  a 
sample  of  tea  rich  in  iron  would,  when  heated  in  the  drying  process, 
become,  by  the  combination  of  this  tannic  acid  with  the  iron  it  con- 
tains, much  darker  than  ordinary  leaves  or  than  other  teas  grown 
upon  less  ferruginous  soils  and  containing  less  iron. 


246  SCIENCE   IN   SHORT   CHAPTERS. 

This  being  the  case,  and  a  commercial  demand  for  black  tea  having 
become  established,  the  tea-grower  would  naturally  seek  to  improve 
the  color  of  his  tea,  especially  of  those  samples  naturally  poor  in 
iron,  and  a  ready  mode  of  doing  this  is  offered  by  stirring  in  among 
the  leaves  while  drying  a  small  additional  dose  of  oxide  of  iron,  if  he 
can  find  an  oxide  in  such  a  form  that  it  will  spread  over  the  surface 
of  the  leaf  as  a  thin  film.  Now,  it  happens  that  the  Chinaman  has 
lying  under  his  feet  an  abundance  of  material  admirably  adapted  for 
this  purpose— viz.  red  hematite,  some  varieties  of  which  are  as  soft 
and  unctuous  as  graphite  and  will  spread  over  his  tea-leaves  exactly 
in  the  manner  required.  The  micaceous  and  silicious  particles 
found  by  Mr.  Bird  are  just  what  should  be  found  in  addition  to  oxide 
of  iron,  if  such  hematite  were  used. 

The  film  of  oxide  thus  easily  applied,  and  subjected  to  the  action 
of  exuding  and  decomposing  extractive  matter  of  the  heated  leaves, 
would  form  the  desired  black  dye  or  "  facing." 

The  knotty  question  of  whether  this  is  or  is  not  an  adulteration  is 
one  that  I  leave  to  lawyers  to  decide,  or  for  those  debating  societies 
that  discuss  such  interesting  questions  as  whether  an  umbrella  is  an 
article  of  dress.  If  it  is  an  adulteration,  and,  as  already  admitted,  is 
not  at  all  injurious  to  health,  then  all  other  operations  of  dyeing  are 
also  adulterations  ;  for  the  other  dyers,  like  the  Chinaman,  add  cer- 
tain impurities  to  their  goods— the  silk,  wool,  or  cotton— in  order  to 
alter  their  natural  appearance,  and  to  give  them  the  false  facing 
which  their  customers  demand,  but  with  this  difference,  if  I  am  right 
in  the  above  explanation  :  that  in  darkening  tea  nothing  more  is 
done  but  to  increase  the  proportion  of  one  of  its  natural  ingredients, 
and  to  intensify  its  natural  color  ;  while  in  the  dyeing  of  silk,  cotton, 
or  wool,  ingredients  are  added  which  are  quite  foreign  and  unnatural, 
and  the  natural  color  of  the  substance  is  altogether  falsified. 

The  above  appeared  in  iheChemical  News,  November  21st,  1873,  when 
the  adulteration  in  question  was  generally  believed  to  be  commonly 
perpetrated,  and  many  unfortunate  shopkeepers  had  been  and  were 
still  being  summoned  to  appear  at  Petty  Sessions,  etc.,  and  publicly 
branded  as  fraudulent  adulterators  on  the  evidence  of  the  newly 
fledged  public  analysts,  who  confidently  asserted  that  they  found 
such  filings  mixed  with  the  tea.  Some  discussion  followed  in  subse- 
quent numbers  of  the  Chemical  News  ;  but  it  only  brought  out  the 
fact  that  "  finely  divided  iron''  exists  in  considerable  quantities  in 
Sheffield — may  be  "  begged, "  as  Mr.  Alfred  H.  Allen  (an  able  analytical 
chemist,  resident  in  Sheffield)  said.  The  fact  that  such  finely  divid- 
ed iron  is  thus  without  commercial  value  still  further  confirms  my 
conclusion  that  it  is  not  used  for  the  adulteration  of  tea.  If  it  were, 
its  collection  would  be  a  regular  business,  and  truck-loads  would  be 
transmitted  from  Sheffield  to  London,  the  great  centre  of  tea-impor- 
tation. No  evidence  of  any  commercial  transactions  in  iron  filings 
or  iron  dust  for  such  purposes  came  forward  in  reply  to  my  chal- 
lenge. The  practical  result  of  the  controversy  is  that  iron  filings 
are  no  longer  to  be  found  in  the  analytical  reports  of  the  adulteration 
of  tea. 


SCIENCE   AND   SPIRITUALISM.  247 

CHAPTER  XXXII. 

SCIENCE  AND  SPIRITUALISM. 

A  BATHER  startling  paper  in  the  current  number  of  the  Quarterly 
Journal  of  Science,  from  the  pen  of  Mr.  William  Crookes,  F.E.S.  (who 
is  well  known  in  the  scientific  world  by  his  discovery  of  the  metal 
thallium,  his  investigations  of  its  properties  and  those  of  its  com- 
pounds, besides  mau}r  other  important  researches,  and  also  as  the 
able  and  spirited  editor  of  the  Chemical  News),  is  now  the  subject  of 
much  scientific  gossip  and  discussion. 

Mr.  Crookes  has  for  some  time  past  been  engaged  in  investigating 
some  of  the  phenomena  which  are  attributed  on  one  hand  to  the 
agency  of  spiritual  visitors,  and  on  the  other  side  to  vulgar  conjur- 
ing. Nobody  acquainted  with  Mr.  Crookes  can  doubt  his  ability  to 
conduct  such  an  investigation,  or  will  hesitate  for  a  moment  in  con- 
cluding that  he  has  done  so  with  philosophical  impartiality,  though 
many  think  it  quite  possible  that  he  may  have  been  deceived.  None, 
however,  can  yet  say  how. 

For  my  own  part,  I  abstain  from  any  conclusion  in  the  mean  time, 
until  I  have  time  and  opportunity  to  witness  a  repetition  of  some  of 
these  experiments,  and  submitting  them  to  certain  tests  which  appear 
to  me  desirable.  Though  struggling  against  a  predisposition  to  pre- 
judge, and  to  conclude  that  the  phenomena  are  the  results  of  some 
very  skilful  conjuring,  I  very  profoundly  respect  the  moral  courage 
that  Mr.  Crookes  has  displayed  in  thus  publicly  grappling  with  a 
subject  which  has  been  soiled  by  contact  with  so  many  dirty  fingers. 
Nothing  but  a  pure  love  of  truth,  overpowering  every  selfish  consid- 
eration, could  have  induced  Mr.  Crookes  to  imperil  his  hard-earned 
scientific  reputation  by  stepping  thus  boldly  on  such  very  perilous 
ground. 

It  is  only  fair,  at  the  outset,  to  state  that  Mr.  Crookes  is  not  what 
is  called  a  "  spiritualist."  This  I  infer,  both  from  what  he  has  pub- 
lished and  from  conversation  I  have  had  with  him  on  the  subject. 
He  has  witnessed  some  of  the  "physical  manifestations,"  and,  while 
admitting  that  many  of  these  may  be  produced  by  the  jugglery  of 
impostors,  he  has  concluded  that  others  cannot  be  thus  explained  ; 
but,  nevertheless,  does  not  accept  the  spiritual  theory  which  at- 
tributes them  to  the  efforts  of  departed  Iranian  souls. 

He  suspects  that  the  living  human  being  may  have  the  power  of 
exerting  some  degree  of  force  or  influence  upon  bodies  external  to 
himself— may,  for  instance,  be  able  to  counteract  or  increase  the 
gravitation  of  substances  by  an  effort  of  the  will.  He  calls  this 
power  the  "  psychic  force,"  and  supposes  that  some  persons  are  able 
to  manifest  it  much  more  powerfully  than  others,  and  thus  explains 
the  performances  of  those  "  mediums"  who  are  not  mere  impostors. 

There  is  nothing  in  this  hypothesis  which  the  sternest,  the  most 
sceptical,  and  least  imaginative  of  physical  philosophers  may  not  un- 
hesitatingly investigate,  provided  some  first  sight  evidence  of  its  pos- 
sibility is  presented  to  him.  We  know  that  the  Torpedo,  the  Gym- 
notus,  the  Silurus  Electricus,  and  other  fishes,  can,  by  an  effort  of 
the  will,  act  upon  bodies  external  to  themselves.  Faraday  showed 
that  the  electric  eel  exhibited  some  years  ago  at  the  Adelaide  Gallery 


248  SCIENCE   IN   SHORT   CHAPTERS. 

was  able,  by  an  effort  of  its  will,  to  make  a  magnetic  needle  suddenly 
turn  30  degrees  aside  from  its  usual  polar  position  ;  that  this  same 
animal  could— still  by  an  effort  of  will— overpower  the  gravitation  of 
pieces  of  gold  leaf,  cause  them  to  be  uplifted  and  outstretched  from 
their  pendent  position,  could  decompose  iodide  of  potassium,  and 
perform  many  other  "physical  manifestations,"  simply  by  a  volun- 
tary nervous  effort,  and  without  calling  in  the  aid  of  any  souls  of 
other  departed  eels. 

Before  this  gymnotus  was  publicly  exhibited  it  was  deposited  at  a 
French  hotel  in  the  neighborhood  of  Leicester  Square.  A  burly  fish- 
monger's man,  named  Wren,  brought  in  the  daily  supply  of  fish  to 
the  establishment,  when  some  of  the  servants  told  him  they  had  an 
eel  so  large  that  he  would  be  afraid  to  pick  it  up.  He  laughed  at  the 
idea  of  being  afraid  of  an  eel,  and  when  taken  to  the  tub  boldly 
plunged  in  both  hands  to  seize  the  fish.  A  hideous  roar  followed 
this  attempt.  Wren  had  experienced  a  demonstration  of  the  "  psychic 
force"  of  the  electrical  eel,  and  his  terror  so  largely  exaggerated  the 
actual  violence  of  the  shock,  that  he  believed  for  the  remainder  of 
his  life  that  he  was  permanently  injured  by  it.  He  had  periodical 
spasms  across  the  chest,  which  could  only  be  removed  by  taking  a 
half-quartern  of  gin.  As  he  was  continually  narrating  his  adventure 
to  public-house  audiences,  and  always  had  a  spasm  on  concluding, 
which  his  hearers  usually  contributed  to  relieve,  the  poor  fellow's  life 
was  actually  shortened  by  the  shock  from  the  gymnotus. 

The  experiments  which  Mr.  Crookes  relates  in  support  of  his 
psychic  force  hypothesis  are  as  follows  :  In  the  first  place  he  con- 
trived an  apparatus  for  testing  Mr.  Home's  alleged  power  of  modify- 
ing the  gravitation  of  bodies.  As  Mr.  Home  requires  to  lay  his 
hands,  or  at  least  his  finger  ends,  upon  the  body  to  be  influenced, 
Mr.  Crookes  attached  one  end  of  a  long  board  to  a  suspended  spring 
steelyard  of  delicate  construction  ;  the  other  end  of  the  board  rested 
on  a  fulcrum  in  such  a  manner  that  one  half  of  the  weight  of  the 
board  was  supported  by  the  fulcrum  and  the  other  half  by  the  steel- 
yard. The  weight  of  the  board  thus  suspended  was  carefully  noted, 
and  Mr.  Home  put  his  fingers  upon  that  end  of  the  board  immedi- 
ately resting  on  the  fulcrum  in  such  a  manner  that  he  could  not  by 
simple  pressure  affect  the  dependent  end  of  the  board. 

Dr.  Huggins,  the  eminent  astronomer,  was  present,  and  also  Ser- 
geant Cox,  besides  Mr.  Crookes.  They  all  watched  Mr.  Home,  the 
board,  and  the  steelyard  ;  they  observed  first  a  vibration  and  fluctua- 
tion of  the  index,  and  finally  that  the  steelyard  indicated  an  increase 
of  weight  amounting  to  about  three  pounds.  Mr.  Crookes  tried  to 
produce  the  same  effect  by  mechanical  pressure  exerted  in  a  similar 
manner,  but  failed  to  do  so.  The  details  of  the  experiment  are  fully 
described  and  illustrated  by  an  engraving. 

Another  and  still  more  striking  experiment  is  described.  Mr. 
Crookes  purchased  a  new  accordion  from  Messrs.  Wheatstone,  and 
himself  constructed  a  wire  cage  open  at  top  and  bottom,  and  large 
enough  for  the  accordion  to  be  suspended  within  it  by  holding  it 
over  the  open  top,  while  the  bottom  of  the  cage  rested  on  the  floor. 
The  accordion  was  then  handed  to  Mr.  Home,  who  held  it  with  one 
hand  by  the  wooden  framework  of  the  bottom  of  the  instrument,  as 
shown  in  an  illustrative  drawing.  The  keys  were  thus  hanging 
downward  and  the  bellows  distended  by  the  weight  of  the  instrument 


SCIENCE   AND    SPIRITUALISM.  249 

thus  pendent.  It  was  then  held  so  that  it  should  be  entirely  sur- 
rounded by  the  wirework  of  the  cage,  and  the  results  were,  as  before, 
watched  keenly  by  Mr.  Crookes,  Dr.  Huggins,  and  Sergeant  Cox. 
After  a  while  the  instrument  began  to  wave  about,  then  the  bellows 
contracted,  and  the  lower  part  (i.e.  the  key-board  end)  rose  a  little, 
presently  sounds  were  produced,  and  finally  the  instrument  played  a 
tune  upon  itself  in  obedience,  as  Mr.  Crookes  supposes,  to  the 
psychic  force  which  Mr.  Home  exerted  upon  it. 

Before  the  publication  of  the  paper  describing  these  experiments  a 
proof  was  sent  to  both  Dr.  Huggins  and  Sergeant  Cox,  and  each  has 
written  a  letter  testifying  to  its  accuracy,  which  letters  are  printed 
with  the  paper  in  the  Quarterly  Journal  of  Science. 

Here,  then,  we  have  the  testimony  of  an  eminent  lawyer,  accus- 
tomed to  sifting  evidence,  that  of  the  most  distinguished  of  experi- 
mental astronomers,  the  man  whose  discoveries  in  celestial  physics 
have  justly  excited  the  admiration  of  the  whole  civilized  world  ;  and 
besides  these,  of  another  Fellow  of  the  Boyal  Society,  who  has  been 
severely  trained  in  "  putting  nature  to  the  torture"  by  means  of  the 
most  subtle  devices  of  the  modern  physical  and  chemical  laboratory. 

Such  testimony  must  not  be  treated  lightly.  It  would  be  simple 
impertinence  for  any  man  dogmatically  to  assert  that  these  have  been 
deceived  merely  because  he  is  unconvinced. 

Though  one  of  the  unconvinced  myself,  I  would  not  dare  to  regard 
the  investigations  of  these  gentlemen  with  any  other  than  the  pro- 
foundest  respect.  Still  a  suggestion  occurs  to  me  which  may  appear 
very  brutal,  but  I  make  it  nevertheless.  It  is  this  :  That  the  testi- 
mony of  another  witness — of  an  expert  of  quite  a  different  school  — 
should  have  been  added.  I  mean  such  a  man  as  Dobler,  Houdin,  or 
the  Wizard  of  the  North.  He  might  possibly  have  detected  some- 
thing which  escaped  the  scrutiny  of  the  legitimate  scientific  experi- 
mentalist. 

There  is  one  serious  defect  in  the  accordion  experiment.  The  cage 
is  represented  in  the  engraving  as  placed  under  a  table  ;  Mr.  Homo 
holds  the  instrument  in  his  hand,  which  is  concealed  by  the  table, 
and  it  does  not  appear  that  either  Mr.  Crookes,  Dr.  Huggins,  or  Ser- 
geant Cox  placed  themselves  under  the  table  during  the  concertina 
performance,  and  thus  neither  of  them  saw  Mr.  Home's  hand.  Such, 
at  least,  appears  from  the  description  and  the  engraving.  A  story 
being  commonly  circulated  respecting  some  of  Mr.  Home's  experi- 
ments in  Kussia,  according  to  which  he  failed  entirely  when  a  glass 
table  was  provided  instead  of  a  wooden  one,  it  would  be  well,  if  only 
in  justice  to  Mr.  Home,  to  get  rid  of  the  table  altogether. 

It  is  very  desirable  that  these  experiments  should  be  continued,  for 
two  distinct  reasons  ;  first,  as  a  matter  of  ordinary  investigation  for 
philosophical  purposes,  and,  secondly,  as  a  means  of  demolishing  the 
most  degrading  superstition  of  this  generation. 

If  Mr.  Crookes  succeeds  in  demonstrating  the  existence  of  the 
psychic  force  and  reducing  it  to  law — as  it  must  be  reducible  if  it  is  a 
force — then  the  ground  will  be  cut  from  under  the  feet  of  spiritual- 
ism, just  as  the  old  superstitions,  which  attributed  thunder  and  light- 
ning to  Divine  anger,  were  finally  demolished  by  Franklin's  kite.  If, 
on  the  other  hand,  the  arch-medium,  Mr.  Home,  is  proved  to  be  a 
common  conjuror,  then  surely  the  dupes  of  the  smaller  "  medium- 
istic':  fry  will  have  their  eyes  opened,  provided  the  cerebral  disturb- 


250  SCIENCE   IN   SHORT   CHAPTERS. 

ance  which  spiritualism  so  often  induces  has  not  gone  so  far  as  to 
render  them  incurable  lunatics. 

It  is  very  likely  that  I  shall  be  accused  of  gross  uncharitableness  in 
thus  applying  the  term  lunatic  to  "those  who  differ  from  me,"  and 
therefore  state  that  I  have  sad  and  sufficient  reasons  for  doing  so. 

The  first  spiritualist  I  ever  knew,  and  with  whom  I  had  many  con- 
ferences on  the  subject  many  years  ago,  was  a  lady  of  most  estimable 
qualities,  great  intellectual  attainments,  and  distinguished  literary 
reputation.  I  watched  the  beginning  and  the  gradual  progress  of  her 
spiritual  "  investigations,"  as  she  called  them,  and  witnessed  the 
melancholy  end— shocking  delusions,  intellectual  shipwreck,  and 
confirmed,  incurable  insanity,  directly  and  unmistakably  produced 
by  the  action  of  these  hideous  superstitions  upon  an  active,  excitable 
imagination. 

I  well  remember  the  growing  symptoms  of  this  case,  have  seen  their 
characteristic  features  repeated  in  others,  and  have  now  before  me 
some  melancholy  cases  where  the  same  changes,  the  same  decline  of 
intellect  and  growth  of  ravenous  credulity,  is  progressing  with  most 
painfully  visible  distinctness. 

The  necessity  for  some  strong  remedy  is  the  more  urgent,  inasmuch 
as  the  diabolical  machinery  of  the  spiritual  impostors  has  been  so 
much  improved  of  late.  The  lady  whose  case  I  first  referred  to  had 
reached  the  highest  stage  of  spiritualistic  development — viz.  the 
lunatic  asylum— before  "  dark  seances"  had  been  invented,  or,  at  any 
rate,  before  they  were  introduced  into  this  country.  When  the  con- 
ditions of  these  seances  are  considered,  it  is  not  at  all  surprising  that 
persons  of  excitable  temperament,  especially  women,  should  be  mor- 
bidly affected  by  them. 

We  are  endowed  with  certain  faculties,  and  placed  in  a  world 
wherein  we  may  exercise  them  healthfully  upon  their  legitimate  ob- 
jects. Such  exercise,  properly  limited,  promotes  the  growth  and 
vigor  of  our  faculties  ;  but  if  we  pervert  them  by  directing  them  to 
illegitimate  objects,  we  gradually  become  mad.  God  has  created  the 
light,  and  fitted  our  eyes  to  receive  it  ;  he  has  endowed  us  with  the 
sense  of  touch,  by  which  we  may  confirm  and  verify  the  impressions 
of  sight.  All  physical  phenomena  are  objects  of  sense,  and  the 
senses  of  sight  and  touch  are  the  masters  of  all  the  other  senses. 

Can  anything,  then,  be  more  atrociously  perverse,  more  utterly 
idiotic,  and  I  may  even  say  impious,  than  these  dark  seance  investi- 
gations? Is  it  possible  to  conceive  a  more  melancholy  spectacle  of 
intellectual  degradation  than  that  presented  by  a  group  of  human 
victims  assembled  for  the  purpose  of  "investigating  physical  mani- 
festations," and  submitting,  as  a  primary  condition,  to  be  blinded 
and  handcuffed,  the  room  in  which  they  sit  being  made  quite  dark, 
and  both  hands  of  each  investigator  being  firmly  held  by  those  of  his 
neighbors.  That  is  to  say,  the  primary  conditions  of  making  these 
physical  investigations  is  that  each  investigator  shall  be  deprived  of 
his  natural  faculties  for  doing  so. 

When  we  couple  this  with  the  fact  that  these  meetings  are  got  up 
— publicly  advertised  by  adventurers  who  make  their  livelihood  by 
the  fees  paid  by  their  hoodwinked  and  handcuffed  customers— is  it 
at  all  surprising  that  those  who  submit  to  such  conditions  should 
finish  their  researches  in  a  lunatic  asylum  ? 

The  gloom,  the  mystery,  the  unearthly  objects  of  search,  the  mys' 


SCIENCE   AN"D   SPIRITUALISM.  251 

terious  noises,  and  other  phenomena  so  easily  manipulated  in  the 
presence  of  those  who  can  see  nothing  and  feel  only  the  sympathetic 
twitching  of  another  pair  of  trembling  hands,  naturally  excites  very 
powerfully  the  poor  creatures  who  pay  their  half-crowns  and  half- 
guineas  with  any  degree  of  faith  ;  and  this  unnatural  excitement,  if 
frequently  repeated,  goes  on  increasing  till  the  brain  becomes  incur- 
ably diseased. 

Present  space  will  not  permit  me  to  enter  upon  another  branch  of 
this  subject,  viz.  the  moral  degradation  and  the  perversion  of  natu- 
ral, unsophisticated,  and  wholesome  theology,  which  these  spiritual 
delusions  are  generating. 

I  am  no  advocate  for  rectifying  moral  and  intellectual  evils  by 
police  interference,  or  I  should  certainly  recommend  the  bracing  air 
of  Dartmoor  for  the  mediums  who  publicly  proclaim  that  their  famil- 
iar spirit  "  Katey"  has  lately  translated  a  lady  through  a  space  of 
three  miles,  and  through  the  walls,  doors,  and  ceiling  of  the  house  in 
which  a  dark  seance  was  being  held,  and  placed  her  upon  the  table 
in  the  midst  of  the  circle  so  rapidly  that  the  word  "  onions"  she  had 
just  written  in  her  domestic  inventory  was  not  yet  dried  when  the 
lights  were  brought  and  she  was  found  there. 

This  "  lady,"  which  her  name  is  Guppy,  is,  of  course,  another  pro- 
fessional medium,  and  yet  there  are  people  in  London  who  gravely 
believe  this  story,  and  also  the  appendix,  viz.  that  another  member 
of  the  mediumistic  firm,  finding  that  Mrs.  G.  was  very  incompletely 
dressed,  and  much  abashed  thereby,  was  translated  by  the  same 
spirit,  Katey,  to  her  house  and  back  again  through  the  door-panel,  to 
fetch  proper  garments.  If  I  could  justify  the  apprehension  and  im- 
prisonment of  poor  gypsy  fortune-tellers,  I  certainly  shoiild  advocate 
the  close  confinement  of  Mrs.  Guppy  and  her  male  associates,  and 
thus  afford  the  potent  spirit,  Katey,  an  opportunity  of  further  mani- 
festation by  translating  them  through  the  prison  walls  and  back  to 
Lamb's  Conduit  Street. 

(T.te  above  letter  appeared  in  the  Birmingham  Morning  News  of  July 
1.8th,  1871  ;  the  following  on  November  15th.  It  refers  to  an  article  in  the 
Quarterly  Review  of  October,  1871.) 

The  interest  excited  by  Mr.  Crookes's  investigations  on  Psychic 
Force  is  increasing  ;  the  demand  for  the  Quarterly  Review  and  the 
Quarterly  Journal  of  Science  is  so  great  that  Mudie  and  other  proprie- 
tors of  lending  libraries  have  largely  increased  their  customary  sup- 
plies, and  are  still  besieged  with  further  excess  of  demand.  Not  only 
borrowers,  but  purchasers  also  are  supplied  with  difficulty.  I  yester- 
day received  a  post-card  from  a  bookseller,  inscribed  as  follows : 
"  Cannot  get  a  Quarterly  Review  in  the  city,  so  shall  be  unable  to  send 
it  to  you  until  to-morrow."  I  have  waited  three  days,  and  am  now 
obliged  to  go  to  the  reading-room  to  make  my  quotations. 

There  is  good  and  sufficient  reason  for  this,  independently  of  the 
absence  of  Parliamentary  and  war  news,  and  the  dearth  of  political 
revolutions.  Either  a  new  and  most  extraordinary  natural  force  has 
been  discovered,  or  some  very  eminent  men  especially  trained  in 
rigid  physical  investigation  have  been  the  victims  of  a  marvellous, 
unprecedented,  and  inexplicable  physical  delusion.  I  say  unprece- 
dented, because,  although  we  have  records  of  many  popular  delu- 
sions of  similar  kind  and  equal  magnitude,  and  speculative  delusions 
among  the  learned,  I  can  cite  no  instance  of  skilful  experimental 


252  SCIENCE   UST   SHORT   CHAPTERS. 

experts  being  utterly  and  repeatedly  deceived  by  the  mechanical 
action  of  experimental  test  apparatus  carefully  constructed  and  used 
by  themselves. 

As  the  interest  in  the  subject  is  rapidly  growing,  my  readers  will 
probably  welcome  a  somewhat  longer  gossip  on  this  than  I  usually 
devote  to  a  single  subject. 

Such  an  extension  is  the  more  demanded  as  the  newspaper  and 
magazine  articles  which  have  hitherto  appeared  have,  for  the  most 
part,  by  following  the  lead  of  the  Quarterly  .Review,  strangely  muddled 
the  whole  subject,  and  misstated  the  position  of  Mr.  Crookes  and 
others.  In  the  first  place,  all  the  writers  who  follow  the  Quarterly 
omit  any  mention  or  allusion  to  Mr.  Crookes's  preliminary  paper 
published  in  July,  1870,  which  has  a  most  important  bearing  on  the 
whole  subject,  as  it  expounds  the  object  of  all  the  subsequent  re- 
searches. 

Mr.  Crookes  there  states  that ' '  Some  weeks  ago  the  fact  that  I  was 
engaged  in  investigating  Spiritualism,  so-called,  was  announced  in  a 
contemporary  (the  Athenceum),  and  in  consequence  of  the  many  com- 
munications I  have  since  received,  I  think  it  desirable  to  say  a  little 
concerning  the  investigations  which  I  have  commenced.  Views  or 
opinions  I  cannot  be  said  to  possess  on  a  subject  which  I  do  not  pro- 
fess to  understand.  I  consider  it  the  duty  of  scientific  men,  who 
have  learned  exact  modes  of  working,  to  examine  phenomena  which 
attract  the  attention  of  the  public,  in  order  to  confirm  their  genuine- 
ness, or  to  explain,  if  possible,  the  delusions  of  the  honest,  and  to 
expose  the  tricks  of  deceivers." 

He  then  proceeds  to  state  the  case  of  Science  versus  Spiritualism 
thus  :  "  The  Spiritualist  tells  of  bodies  weighing  50  or  100  Ibs.  be- 
ing lifted  up  into  the  air  without  the  intervention  of  any  known 
force  ;  but  the  scientific  chemist  is  accustomed  to  use  a  balance 
which  will  render  sensible  a  weight  so  small  that  it  would  take  ten 
thousand  of  them  to  weigh  one  grain  ;  he  is,  therefore,  justified  in 
asking  that  a  power,  professing  to  be  guided  by  intelligence,  which 
will  toss  a  heavy  body  to  the  ceiling,  shall  also  cause  his  delicately- 
poised  balance  to  move  under  test  conditions."  "  The  Spiritualist 
tells  of  rooms  and  houses  being  shaken,  even  to  injury,  by  superhu- 
man power.  The  man  of  science  merely  asks  for  a  pendulum  to  be 
sent  vibrating  when  it  is  in  a  glass-case,  and  supported  on  solid 
masonry.  "t  "  The  Spiritualist  tells  of  heavy  articles  of  furniture 
moving  from  one  room  to  another  without  human  agency.  But  the 
man  of  science  has  made  instruments  which  will  divide  an  inch  into 
a  million  parts,  and  he  is  justified  in  doubting  the  accuracy  of  the 
former  observations,  if  the  same  force  is  powerless  to  move  the  index 
of  his  instrument  one  poor  degree."  <;  The  Spiritualist  tells  of 
flowers  with  the  fresh  dew  on  them,  of  fruit,  and  living  objects  being 
carried  through  closed  windows,  and  even  solid  brick  walls.  The 
scientific  investigator  nattirally  asks  that  an  additional  weight  (if  it 
be  only  the  1000th  part  of  a  grain)  be  deposited  on  one  pan  of  his 
balance  when  the  case  is  locked.  And  the  chemist  asks  for  the 
1000th  part  of  a  grain  of  arsenic  to  be  carried  through  the  sides  of  a 
gas  tube  in  which  pure  water  is  hermetically  sealed. ' ' 

These  and  other  requirements  are  stated  by  Mr.  Crookes,  together 
with  further  exposition  of  the  principles  of  strict  inductive  investiga- 
tion, as  it  should  be  applied  to  such  an  inquiry.  A  year  after  this  he 


SCIENCE   AKD   SPIRITUALISM.  253 

published  an  account  of  the  experiments  which  I  described  in  a 
former  letter,  and  added  to  his  own  testimony  that  of  the  eminent 
physicist  and  astronomer  Dr.  Huggins,  and  Sergeant  Cox.  Subse- 
quently, that  is,  in  the  last  number  of  the  Quarterly  Journal  of  Science, 
he  has  published  the  particulars  of  another  series  of  experiments. 

I  will  not  now  enter  upon  the  details  of  these,  but  merely  state 
that  the  conclusions  of  Mr.  Crookes  are  directly  opposed  to  those  of 
the  Spiritualists.  He  positively,  distinctly,  and  repeatedly  repudi- 
ates all  belief  in  the  operations  of  the  supposed  spirits,  or  of  any 
other  supernatural  agency  whatever,  and  attributes  the  phenomena 
he  witnessed  to  an  entirely  different  origin,  viz.  to  the  direct  agency 
of  the  medium.  He  supposes  that  a  force  analogous  to  that  which 
the  nerves  convey  from  their  ganglionic  centres  to  the  muscles,  in 
producing  muscular  contraction,  may  by  an  effort  of  the  will  be 
transmitted  to  external  inanimate  matter,  in  such  a  manner  as  to  in- 
fluence, in  some  degree,  its  gravitating  power,  and  produce  vibratory 
motion.  He  calls  this  the  psychic  force. 

Now,  this  is  direct  and  unequivocal  anft-spi ritualism.  It  is  a 
theory  set  up  in  opposition  to  the  supernatural  hypotheses  of  the 
Spiritualists,  and  Mr.  Crookes 's  position  in  reference  to  Spiritualism 
is  precisely  analogous  to  that  of  Faraday  in  reference  to  table-turn- 
ing. For  the  same  reasons  as  those  above  quoted,  the  great  master  of 
experimental  investigation  examined  the  phenomena  called  table- 
turning,  and  he  concluded  that  they  were  due  to  muscular  force,  just 
as  Mr.  Crookes  concludes  that  the  more  complex  phenomena  he  has 
examined  are  due  to  psychic  force. 

Speaking  of  the  theories  of  the  Spiritualists,  Mr.  Crookes,  in  his 
first  paper  (July,  1870),  says  :  "  The  pseudo- scientific  Spiritualist 
professes  to  know  everything.  No  calculations  trouble  his  serenity  ; 
no  hard  experiments,  no  laborious  readings  ;  no  weary  attempts  to 
make  clear  in  words  that  which  has  rejoiced  the  heart  and  elevated 
the  mind.  He  talks  glibly  of  all  sciences  and  arts,  overwhelming  the 
inquirer  with  terms  like  '  electro-biologize,'  '  psychologize,'  '  animal 
magnetism,'  etc.,  a  mere  play  upon  words,  showing  ignorance  rather 
than  understanding."  And  further  on  he  says  :  "I  confess  that  the 
reasoning  of  some  Spiritualists  would  almost  seem  to  justify  Fara- 
day's severe  statement — that  many  dogs  have  the  power  of  coming  to 
more  logical  conclusions." 

I  have  already  referred  to  the  muddled  misstatement  of  Mr. 
Crookes 's  position  by  the  newspaper  writers,  who  almost  unani- 
mously describe  him  and  Dr.  Huggins  as  two  distinguished  scientific 
men  who  have  recently  been  converted  to  Spiritualism.  The  above 
quotations,  to  which,  if  space  permitted,  I  might  add  a  dozen  others 
from  either  the  first,  the  second,  or  third  of  Mr.  Crookes's  papers,  in 
which  he  as  positively  and  decidedly  controverts  the  dreams  of  the 
Spiritualists,  will  show  how  egregiously  these  writers  have  been  de- 
ceived. They  have  relied  very  naturally  on  the  established  respecta- 
bility of  the  Quarterly  Review,  and  have  thus  deluded  both  themselves 
and  their  readers.  Considering  the  marvellous  range  of  subjects 
these  writers  have  to  treat,  and  the  acres  of  paper  they  daily  cover,  it 
is  not  surprising  that  they  should  have  been  thus  misled  in  reference 
to  a  subject  carrying  them  considerably  out  of  their  usual  track  ;  but 
the  oifeuce  of  the  Quarterly  is  not  so  venial.  It  assumes,  in  fact,  a 
very  serious  complexion  when  further  investigated. 


254  SCIENCE   IN   SHOET   CHAPTERS. 

The  title  of  the  article  is  "  Spiritualism  and  its  Recent  Converts," 
and  the  "  recent  converts"  most  specially  and  prominently  named 
are  Mr.  Crookes  and  Dr.  Huggins.  Sergeant  Cox  is  also  named,  but 
not  as  a  recent  convert  ;  for  the  reviewer  describes  him  as  an  old  and 
hopelessly  infatuated  Spiritualist.  Knowing  nothing  of  Sergeant 
Cox,  I  am  unable  to  say  whether  the  reviewer's  very  strong  personal 
statements  respecting  him  are  true  or  false — whether  he  really  ift 
"one  of  the  most  gullible  of  the  gullible,"  etc.,  though  I  must  pro- 
test against  the  bad  taste  which  is  displayed  in  the  attack  which  is 
made  upon  this  gentleman.  The  head  and  front  of  his  offending 
cons  sts  in  having  certified  to  the  accuracy  of  certain  experiments  ; 
and  for  having  simply  done  this,  the  reviewer  proceeds,  in  accord- 
ance with  the  lowest  tactics  of  Old  Bailey  advocacy,  to  bully  the  wit- 
ness, and  to  publish  disparaging  personal  details  of  what  he  did 
twenty-five  years  ago. 

Dr.  Huggins,  who  has  had  nothing  further  to  do  with  the  subject 
than  simply  to  state  that  he  witnessed  what  Mr.  Crookes  described, 
and  who  has  not  ventured  upon  one  word  of  explanation  of  the  phe- 
nomena, is  similarly  treated. 

The  reviewer  goes  out  of  his  way  to  inform  the  public  that  Dr. 
Huggins  is,  after  all,  only  a  brewer,  by  artfully  stating  that,  "  like 
Mr.  Whitbread,  Mr.  Lassell,  and  other  brewers  we  could  name,  Dr. 
Huggins  attached  himself  in  the  first  place  to  the  study  of  astron- 
omy." He  then  proceeds  to  sneer  at  "  such  scientific  amateurs,"  by 
informing  the  public  that  they  "  labor,  as  a  rule,  under  a  grave  dis- 
advantage, in  the  want  of  that  broad  basis  of  scientific  culture  which 
alone  can  keep  them  from  the  narrowing  and  pervertive  influence  of 
a  limited  specialism." 

The  reviewer  proceeds  to  say  that  he  has  "  no  reason  to  believe 
that  Dr.  Huggins  constitutes  an  exception"  to  this  rule,  and  further 
asserts  that  he  is  justified  in  concluding  that  Dr.  Huggins  is  ignorant 
of  "  every  other  department  of  scrence  than  the  small  subdivision  of  a 
branch  to  which  he  has  so  meritoriously  devoted  himself. "  Mark  the 
words,  "  small  subdivision  of  a  branch."  Merely  a  twig  of  the  tree 
of  science  is,  according  to  this  most  unveracicus  writer,  all  that  Dr. 
Huggins  has  ever  studied. 

If  a  personal  vindication  were  the  business  of  this  letter  I  could 
easily  show  that  these  statements  respecting  the  avocations,  the  sci- 
entific training,  and  actual  attainments  of  Dr.  Huggins  are  gross  and 
atrocious  misrepresentations  ;  but  Dr.  Huggins  has  no  need  of  my 
championship  ;  his  high  scientific  position,  the  breadth  and  depth 
of  his  general  attainments,  and  the  fact  that  he  is  not  Huggins  the 
brewer,  are  sufficiently  known  to  all  in  the  scientific  world,  with  the 
exception  of  the  Quarterly  reviewer. 

My  object  is  not  to  cliscuss  the  personal  question  whether  book- 
making  and  dredging  afford  better  or  worse  training  for  experimental 
inquiry  than  the  marvellously  exact  and  exquisitely  delicate  manipu- 
lations of  the  modern  observatory  and  laboratory,  but  to  protest 
against  this  attempt  to  stop  the  progress  of  investigation,  to  damage 
the  true  interests  of  science  and  the  cause  of  truth,  by  throwing  low 
libellous  mud  upon  any  and  everybody  who  steps  at  all  aside  from 
the  beaten  paths  of  ordinary  investigation. 

The  true  business  of  science  is  the  discovery  of  truth  ;  to  seek  it 
wherever  it  may  be  found,  to  pursue  it  through  byways  as  well  as 


SCIENCE   AND   SPIRITUALISM.  255 

highways,  and,  having  found  it,  to  proclaim  it  plainly  and  fearlessly, 
without  regard  to  authority,  fashion,  or  prejudice.  If,  however, 
such  influential  magazines  as  the  Quarterly  Review  are  to  be  converted 
into  the  vehicles  of  artful  and  elaborate  efforts  to  undermine  the 
scientific  reputation  of  any  man  who  thus  does  his  scientific  duty, 
the  time  for  plain  speaking  and  vigorous  protest  has  arrived. 

My  readers  will  be  glad  to  learn  that  this  is  the  general  feeling  of 
the  leading  scientific  men  of  the  metropolis  ;  whatever  they  may 
think  of  the  particular  investigations  of  Mr.  Crookes,  they  are  unani- 
mous  in  expressing  their  denunciations  of  this  article. 

The  attack  upon  Mr.  Crookes  is  still  more  malignant  than  that  of 
Dr.  Huggins.  Speaking  of  Mr.  Crookes 's  fellowship  of  the  Royal 
Society,  the  reviewer  says  :  "  We  speak  advisedly  when  we  say  that 
this  distinction  was  conferred  on  him  with  Considerable  hesitation;"  and 
further  that  "  We  are  assured,  on  the  highest  authority,  that  he  is 
regarded  among  chemists  as  a  specialist  of  specialists,  being  totally 
destitute  of  any  knowledge  of  chemical  philosophy,  and  utterly  untrustworthy 
as  to  any  inquiry  which  requires  more  than  technical  knowledge  for  its  suc- 
cessful conduct. ' ' 

The  italics  in  these  quotations  are  my  own,  placed  there  to  mark 
certain  statements  to  which  no  milder  term  than  that  of  falsehood  is 
applicable.  The  history  of  Mr.  Crookes 's  admission  to  the  Royal 
Society  will  shortly  be  published,  when  the  impudence  of  the  above 
statement  respecting  it  wrill  be  unmasked  ;  and  the  other  quotations 
I  have  emphasized  are  sufficiently  and  abundantly  refuted  by  Mr. 
Crookes 's  published  works,  and  his  long  and  able  conduct  of  the 
Chemical  News,  which  is  the  only  and  the  recognized  British  periodi- 
cal representative  of  chemical  science. 

If  space  permitted,  I  could  go  on  quoting  a  long  series  of  misstate- 
ments  of  matters  of  fact  from  this  singularly  unveracious  essay.  The 
•writer  seems  conscious  of  its  general  character,  for,  in  the  midst  of 
one  of  his  narratives,  he  breaks  out  into  a  foot-note,  stating  that 
"  this  is  not  an  invention  of  our  own,  but  a  fact  communicated  to  us 
by  a  highly  intelligent  witness,  who  was  admitted  to  one  of  Mr. 
Crookes 's  seances. "  I  have  taken  the  liberty  to  emphasize  the  proper 
word  in  this  very  explanatory  note. 

The  full  measure  of  the  injustice  of  prominently  thrusting  forward 
Dr.  Huggins  and  Mr.  Crookes  as  "recent  converts"  to  Spiritualism 
will  be  seen  by  comparing  the  reviewer's  own  definition  of  Spiritual- 
ism with  Mr.  Crookes 's  remarks  above  quoted.  The  reviewer  says 
that  "  The  fundamental  tenet  of  the  Spiritualist  is  the  old  doctrine 
of  communication  between  the  spirits  of  the  departed  and  souls  of 
the  living." 

This  is  the  definition  of  the  reviewer,  and  his  logical  conclusion  is 
that  Mr.  Crookes  is  a  Spiritualist  because  he  explicitly  denies  the 
fundamental  tenet  of  Spiritualism,  and  Dr.  Huggins  is  a  Spiritualist 
because  he  says  nothing  whatever  about  it. 

If  examining  the  phenomena  upon  which  the  Spiritualist  builds 
his  "  fundamental  tenet,"  and  explaining  them  in  some  other  man- 
ner, constitutes  conversion  to  Spiritualism,  then  the  reviewer  is  a  far 
more  thorough-going  convert  than  Mr.  Crookes,  who  only  attempts  to 
explain  the  mild  phenomena  'of  his  own  experiments,  while  the 
reviewer  goes  in  for  everything,  including  even  the  apotheosis  of 
Mrs.  Guppy  and  her  translation  through  the  ceiling,  a  story  which  is 


256  SCIEXCE   IIS"   SHORT   CHAPTERS. 

laughed  at  by  Mr.  Crookes  and  everybody  else,  excepting  a  few  of  the 
utterly  crazed  disciples  of  the  "  Lamb's  Conduit  Mediums"  and  the 
Quarterly  reviewer,  who  actually  attempts  to  explain  it  by  his  infalli- 
ble and  ever  applicable  physiological  nostrum  of  "  unconscious 
cerebration." 

No  marvellous  story  either  of  ancient  or  modern  date  is  too  strong 
for  this  universal  solvent,  which,  according  to  the  reviewer,  is  the 
sole  and  glorious  invention  of  Dr.  Carpenter.  Space  will  not  now 
permit  me  to  further  describe  "  unconscious  cerebration"  and  its 
vast  achievements,  but  I  hope  to  find  a  corner  for  it  hereafter, 

I  may  add  that  the  name  of  the  reviewer  is  kept  a  profound  secret, 
and  yet  is  perfectly  well  known,  as  everybody  who  reads  the  article 
finds  it  out  when  he  reaches  those  parts  which  describe  Dr.  Carpen- 
ter's important  physiological  researches  and  discoveries. 


CHAPTER  XXXIII. 

MATHEMATICAL  FICTIONS    (BRITISH   ASSOCIATION,  1871). 

THE  President's  inaugural  address,  which  was  going  through  the 
press  in  London  while  being  spoken  in  Edinburgh,  has  already  been 
subject  to  an  unusual  amount  of  sharp  criticism.  For  my  own  part 
I  cannot  help  regarding  it  as  one  of  the  least  satisfactory  of  all  the 
inaugural  addresses  that  have  yet  been  delivered  at  these  annual 
meetings.  They  have  been  of  two  types,  the  historical  and  the  con- 
troversial ;  the  former  prevailing.  In  the  historical  addresses  the 
President  has  usually  made  a  comprehensive  and  instructive  survey 
of  the  progress  of  the  whole  range  of  science  during  the  past  year, 
and  has  dwelt  more  particularly  on  some  branch  which  from  its  own 
intrinsic  merits  has  claimed  special  attention,  or  which  his  own  spe- 
cial attainments  have  enabled  him  to  treat  with  the  greatest  ability 
and  authority.  A  few  Presidents  have,  like  Dr.  Huxley  last  year, 
taken  up  a  particular  subject  only,  and  have  discussed  it  more  thor- 
oughly than  they  could  have  done  had  they  also  attempted  a  general 
historical  survey. 

Every  President  until  1871  has  scrupulously  kept  in  view  his  judi- 
cial position,  and  the  fact  that  he  is  addressing,  not  merely  a  few 
learned  men,  but  the  whole  of  England,  if  not  the  whole  civilized 
world.  They  have  therefore  clearly  distinguished  between  the  es- 
tablished and  the  debatable  conclusions  of  science,  between  ascer- 
tained facts  and  mere  hypotheses,  have  kept  this  distinction  so 
plainly  before  their  auditors  that  even  the  most  uninitiated  could 
scarcely  confound  the  one  with  the  other. 

In  Sir  William  Thomson's  address  this  desirable  rule  is  recklessly 
violated.  He  tells  his  unsophisticated  audience  that  Joule  was  able 
"  to  estimate  the  average  velocity  of  the  ultimate  molecules  or 
atoms"  of  gases,  and  thus  determined  the  atomic  velocity  of  hydro- 
gen, "at  6225  feet  per  second  at  temperature  60°  Fahr.,  and  6055 
feet  at  the  freezing  point  ;"  that  "  Clausius  took  fully  into  account 
the  impacts  of  molecules  upon  one  another,  and  the  kinetic  energy 


MATHEMATICAL   FICTIONS.  267 

of  relative  motion  of  the  matter  constituting  an  individual  atom  ;"  and 
that  ' '  he  investigated  the  relation  between  their  diameters,  the  num- 
ber in  a  given  space,  and  the  mean  length  of  path  from  impact  to 
impact,  and  so  gave  the  foundation  for  estimates  of  the  absolute 
dimensions  of  atoms."  Also  that  "  Loschmidt,  in  Vienna,  had 
shown,  and  not  much  later  Stoney,  independently,  in  England,  show- 
ed how  co  reduce  from  Clausius  and  Maxwell's  kinetic  theory  of  gases 
a  superior  limit  to  the  number  of  atoms  in  a  given  measurable  space." 

The  confiding  auditor  follows  the  President  through  further  dis- 
quisitions on  the  "  superlatively  grand  question,  what  is  the  inner 
mechanism  of  an  atom  ?"  and  a  minute  and  most  definite  description 
of  the  "regular  elastic  vibrations"  of  "the  ultimate  atom  of 
sodium,"  of  the  manner  in  which  "  any  atom  of  gas,  when  struck 
and  left  to  itself,  vibrates  with  perfect  purity  its  fundamental  note  or 
notes,"  and  how,  "  in  a  highly  attenuated  gas,  each  atom  is  very 
rarely  in  collision  with  other  atoms,  and  therefore  is  nearly  at  all 
times  in  a  state  of  true  vibration,"  while  "  in  denser  gases  each  atom 
is 'frequently  in  collision  ;"  besides  a  great  deal  more,  in  all  of  which 
the  existence  of  these  atoms  is  coolly  taken  for  granted,  and  treated 
as  a  fundamental  established  scientific  fact. 

After  hearing  all  these  oracular  utterances  concerning  atoms,  the 
unsophisticated  listener  before  mentioned  will  be  surprised  to  learn 
that  no  human  being  has  ever  seen  an  atom  of  any  substance  what- 
ever ;  that  there  exists  absolutely  no  direct  evidence  of  the  existence 
of  any  such  atoms  ;  that  all  these  atoms  of  which  Sir  W.  Thomson 
speaks  so  confidently  and  familiarly,  and  dogmatically,  are  pure  fig- 
ments of  the  imagination. 

He  will  be  still  further  surprised  to  learn  that  the  bare  belief  in 
the  existence  of  ultimate  atoms  as  a  merely  hypothetical  probability 
is  rejected  by  many  of  the  most  eminent  of  scientific  men,  and  that 
among  those  who  have  disputed  the  idea  of  the  atomic  constitution 
of  matter,  is  the  great  Faraday  himself  ;  that  the  question  of  the 
existence  or  non-existence  of  atoms  has  recently  been  rather  keenly 
discussed  ;  and  that  even  on  the  question  of  the  permissibility  of  ad- 
mitting their  hypothetical  existence,  scientific  opinion  is  divided  ;  and 
that  such  a  confident  assumption  of  their  existence  as  forms  the  basis 
of  this  part  of  the  President's  address  is  limited  to  only  a  small  sec- 
tion of  mutually  admiring  transcendental  mathematicians,  Sir  W. 
Thomson  being  the  most  admired  among  them,  as  shown  by  the 
address  of  Professor  Tait  to  Section  A. 

It  would  have  been  perfectly  legitimate  and  most  desirable  that  Sir 
"W.  Thomson  should  give  the  fullest  and  most  favorable  possible 
statement  of  the  particular  hypotheses  upon  which  he  and  his  friends 
have  exercised  their  unquestionably  great  mathematical  skill  ;  but  he 
should  have  stated  them  as  what  they  are,  and  for  what  they  are 
worth,  and  have  clearly  distinguished  between  such  hypotheses  and 
the  established  facts  of  universally  admitted  science.  Instead  of 
doing  this,  he  has  so  mixed  up  the  actual  discoveries  of  indisputable 
facts  with  these  mere  mathematical  fancies  as  to  give  them  both  the 
semblance  of  equally  authoritative  scientific  acceptance,  and  thus, 
without  any  intention  to  deceive  anybody,  must  have  misled  nearly 
all  the  outside  public  who  have  heard  or  read  his  address. 

As  these  letters  are  mainly  intended  for  those  who  are  too  much 
engaged  in  other  pursuits  to  study  science  systematically,  and  as 


258  SCIENCE   IN   SHORT   CHAPTEES. 

most  of  the  readers  of  such  letters  will,  as  a  matter  of  course,  read 
the  inaugural  address  of  the  President  of  the  British  Association,  I 
have  accepted  the  duty  of  correcting  among  my  own  readers  the  false 
impression  which  this  address  may  create. 

As  a  set-off  to  the  authoritative  utterances  of  Sir  "W.  Thomson  on 
the  subject  of  atoms,  I  quote  the  following  from  an  Italian  philoso- 
pher, who,  during  the  present  year,  is  holding  in  Italy  a  position  very 
similar  to  that  of  the  annual  President  of  our  British  Association. 

Professor  Cannizzaro  has  been  elected  by  a  society  of  Italian  chem- 
ists to  act  as  this  year's  director  of  a  Chronicle  of  the  Progress  of 
Chemical  Science  in  Italy  and  abroad.  In  this  capacity  he  has  pub- 
lished an  inaugural  treatise  on  the  history  of  modern  chemical 
theory,  in  the  course  of  which  he  thus  speaks  of  the  over-confident 
atomic  theorists  :  "  They  often  speak  on  molecular  subjects  with 
as  much  dogmatic  assurance  as  though  they  had  actually  realized  the 
ingenious  fiction  of  Laplace — had  constructed  a  microscope  by  which 
they  could  detect  the  molecules,  and  observe  the  number,  forms,  and 
arrangements  of  their  constituent  atoms,  and  even  determine  the 
direction  and  intensity  of  their  mutual  actions.  Many  of  these 
things,  offered  at  what  they  are  worth — that  is,  as  hypotheses  more 
or  less  probable,  or  as  simple  artifices  of  the  intellect — may  serve, 
and  really  have  served,  to  collocate  facts  and  incite  to  further  investi- 
gations which,  one  day  or  other,  may  lead  to  a  true  chemical  theory  ; 
but,  when  perverted  by  being  stated  as  truths  already  demonstrated, 
they  falsify  the  intellectual  education  of  the  students  of  inductive 
science,  and  bring  reproach  on  the  modern  progress  of  chemistry." 

I  translate  the  above  from  the  first  page  of  the  first  number  of  the 
Gazetta  Chimica  Italiana,  published  at  Palermo  in  January  last.  Had 
these  words  been  written  in  Edinburgh  on  the  evening  of  the  2d  of 
August,  in  direct  application  to  Sir  William  Thomson's  address,  they 
could  not  have  described  more  pointedly  and  truly  the  prevailing 
vice  of  this  production.  If  space  permitted,  I  could  go  further  back 
and  quote  the  words  of  Lord  Bacon,  from  the  great  text-book  of  in- 
ductive philosophy,  wherein  he  denounces  the  worship  of  all  such 
intellectual  idols  as  our  modern  mathematical  dreamers  have  created, 
and  which  they  so  fervently  adore. 

An  able  writer  in  the  Daily  News  of  last  Friday  is  very  severe  upon 
the  biological  portion  of  the  President's  address,  which  contains  a 
really  original  hypothesis.  Sir  W.  Thomson  having  stated  that  he  is 
"  ready  to  adopt  as  an  article  of  scientific  faith,  true  through  all 
space  and  through  all  time,  that  life  proceeds  from  life,  and  from 
nothing  but  life, ' '  asks  the  question,  ' '  How  then  did  life  originate  on 
the  earth  ?"  and  tells  us  that  "  if  a  probable  solution  consistent  with 
the  ordinary  course  of  nature  can  be  found,  we  must  not  invoke  an 
abnormal  act  of  creative  power." 

He  assumes,  with  that  perfect  confidence  in  mathematical  hypothe- 
ses which  is  characteristic  of  the  school  of  theorists  which  he  leads, 
that  "  tracing  the  physical  history  of  the  earth  backward,  on  strictly 
dynamical  principles,  we  are  brought  to  a  red-hot  melted  globe,  on 
which  no  life  could  exist  ;"  and  then,  to  account  for  the  beginning  of 
life  on  our  earth  as  it  cooled  down,  he  creates  another  imaginary 
world,  which  he  brings  in  collision  with  a  second  similar  creation, 
and  thereby  shatters  it  to  fragments.  He  further  imagines  that  one 
of  these  imaginary  broken-up  worlds  was  already  stocked  with  the 


WORLD-SMASHING.  259 

sort  of  life  which  he  says  can  only  proceed  from  life,  and  that  from 
such  a  world  thus  stocked  and  thus  smashed  "  many  great  and  small 
fragments  carrying  seed  and  living  plants  and  animals  would  un- 
doubtedly be  scattered  through  space  ;"  and  that  "  if  at  the  present 
instant  no  such  life  existed  upon  this  earth,  one  such  stone  falling 
upon  it  might,  by  what  we  blindly  call  natural  causes,  lead  to  its  be- 
coming covered  with  vegetation." 

The  conclusion  of  this  paragraph  is  instructively  characteristic  of 
the  philosophy  of  Sir  William  Thomson  and  his  admirers.  He  says 
that  "  the  hypothesis  that  life  originated  on  this  earth  through  moss- 
grown  fragments  of  another  world  may  seem  wild  and  visionary  ;  all  I 
maintain  is  that  it  is  not  unscientific." 

I  have  italicized  the  phrases  which,  put  together,  express  the  phi- 
losophy of  this  school  of  modern  manufacturers  of  mathematical 
hypotheses.  It  matters  not  to  them  how  "  wild  and  visionary, "  how 
utterly  gratuitous  any  assumption  may  be,  it  is  not  unscientific  pro- 
vided it  can  be  invested  in  formulae,  and  worked  out  mathematically. 
These  transcendental  mathematicians  are  struggling  to  carry  philoso- 
phy back  to  the  era  of  Duns  Scotns,  when  the  greatest  triumph  of 
learning  was  to  sophisticate  so  profoundly  an  obvious  absurdity  that 
no  ordinary  intellect  could  refute  it. 

Fortunately  for  the  progress  of  humanity,  there  are  other  learned 
men  who  firmly  maintain  that  the  business  of  science  is  the  dis- 
covery and  teaching  of  simple  sober  truth. 

The  writer  of  the  Daily  News  article  above  referred  to  very  charita- 
bly suggests  that  Sir  W.  Thomson  may  be  "  poking  fun  at  some  of 
his  colleagues,"  and  compares  the  moss-grown  meteorite  hypothesis 
with  the  Hindoo  parable  which  explains  the  stability  of  the  earth  by 
stating  that  it  stands  on  the  back  of  a  monster  tortoise,  that  the  tor- 
toise rests  upon  the  back  of  a  gigantic  elephant,  which  stands  upon 
the  shell  of  a  still  .bigger  tortoise,  resting  on  the  back  of  another  still 
more  gigantic  elephant,  and  so  on.  Sir  W.  Thomson,  of  course, 
requires  to  smash  two  more  worlds  in  order  to  provide  a  moss-grown 
fragment  for  starting  the  life  upon  the  world  which  was  broken  up 
for  our  benefit  and  so  on  backward  ad  infinitum. 


CHAPTER  XXXIY. 

WOELD-SMASHING. 

SIB  W.  THOMSON'S  moss-grown  fragment  of  a  shattered  world  is  not 
yet  forgotten.  In  the  current  number  of  the  Cornhill  Magazine  (Janu- 
ary, 1872)  it  is  very  severely  handled  ;  ihe  more  severely,  because  the 
writer,  though  treating  the  subject  quite  popularly,  shows  the  fallacy 
of  the  hypothesis,  even  when  regarded  from  the  point  of  view  of  Sir 
W.  Thomson's  own  special  department  of  study.  That  an  eminent 
mathematician  should  make  a  great  slip  when  he  ventures  upon  geo- 
logical or  physiological  ground  is  not  at  all  surprising  ;  it  is,  in  fact, 
quite  to  be  expected,  as  there  can  be  no  doubt  that  the  close  study  of 
pure  mathematics,  by  directing  the  mind  to  processes  of  calculation 


260  SCIENCE   IN   SHORT   CHAPTERS. 

rather  than  to  phenomena,  induces  that  sublime  indifference  to  facts 
which  has  characterized  the  purely  mathematical  intellect  of  all  ages. 

It  is  not  surprising  that  a  philosopher  who  has  been  engaged  in 
measuring  the  imaginary  diameter,  describing  the  imaginary  oscilla- 
tions and  gyrations  of  imaginary  atoms,  and  the  still  more  complex 
imaginary  behavior  of  the  imaginary  constituents  of  the  imaginary 
atmospheres  by  which  the  mathematical  imagination  has  surrounded 
these  imaginary  atoms,  should  overlook  the  vulgar  fact  that  neither 
mosses  nor  other  vegetables,  nor  even  their  seeds,  can  possibly  retain 
their  vitality  when  ultimately  exposed  to  the  temperature  of  a  blast 
furnace,  and  that  of  two  or  three  hundred  degrees  below  the  freezing 
point  ;  but  it  is  rather  surprising  that  the  purely  mathematical  basis 
of  this  very  original  hypothesis  of  so  great  a  mathematician  should  be 
mathematically  fallacious — in  plain  language,  a  mathematical  blunder. 

In  order  to  supply  the  seed-bearing  meteoric  fragment  by  which 
each  planet  is  to  be  stocked  with  life,  it  is  necessary,  according  to 
Sir  W.  Thomson,  that  two  worlds — one  at  least  flourishing  with  life — 
shall  be  smashed  ;  and,  in  order  to  get  them  smashed  with  a  suffi- 
cient amount  of  frequency  to  supply  the  materials  for  his  hypothesis, 
the  learned  President  of  the  British  Association  has,  in  accordance 
•with  the  customary  ingenuity  of  mathematical  theorists,  worked  out 
the  necessary  mathematical  conditions,  and  states  with  unhesitating 
mathematical  assurance  that— "  It  is  as  sure  that  collisions  must 
occur  between  great  masses  moving  through  space,  as  it  is  that  ships, 
steered  without  intelligence  directed  to  prevent  collision,  could  not 
cross  and  recross  the  Atlantic  for  thousands  of  years  with  immunity 
from  collision." 

The  author  of  the  paper  in  the  Cornhill  denies  this  very  positively, 
and  without  going  into  the  mathematical  details,  points  out  the  basis 
upon  which  it  may  be  mathematically  refuted — viz.  that  all  such 
worlds  are  travelling  in  fixed  or  regular  orbits  around,  their  primaries 
or  suns,  while  each  of  these  primaries  travels  in  its  own  necessary 
path,  carrying  with  it  all  its  attendants,  which  still  move  about  him, 
just  as  though  he  had  no  motion  of  his  own. 

These  are  the  conclusions  of  Newtonian  dynamics,  the  sublime 
simplicity  of  which  contrasts  so  curiously  with  the  complex  dreams 
of  the  modern  atom-splitters,  and  which  make  a  further  and  still 
more  striking  contrast  by  their  exact  and  perfect  accordance  with 
actual  and  visible  phenomena. 

Newton  has  taught  us  that  there  can  be  no  planets  travelling  at 
random  like  the  Sir  W.  Thomson's  imaginary  ships  with  blind  pilots, 
and  by  following  up  his  reasoning,  we  reach  the  conclusion,  that 
among  all  the  countless  millions  of  worlds  that  people  the  infinity  of 
space,  there  is  no  more  risk  of  collision  than  there  is  between  any 
two  of  the  bodies  that  constitute  our  own  solar  system. 

All  the  observations  of  astronomers,  both  before  and  since  the  dis- 
covery of  the  telescope,  confirm  this  conclusion.  The  long  nightly 
watching  of  the  Chaldean  shepherds,  the  star-counting,  star-gauging, 
star-mapping,  and  other  laborious  gazing  of  mediaeval  and  modern 
astronomers,  have  failed  to  discover  any  collision,  or  any  motion 
tending  to  collision,  among  the  myriads  of  heavenly  bodies  whose 
positions  and  movements  have  been  so  faithfully  and  diligently 
studied.  Thus,  the  hypothesis  of  creation  which  demands  the  destruc- 
tion of  two  worlds  in  order  to  effect  the  sowing  of  a  seed,  is  as 


WORLD-SMASHIKG.  261 

inconsistent  with  sound  dynamics  as  it  is  repugnant  to  common 
sense. 

This  subject  suggests  a  similar  one,  which  was  discussed  a  few 
months  since  at  the  Academy  of  Sciences  of  Paris.  On  January  30th 
last  M.  St.  Meunier  read  a  paper  on  "  The  mode  of  rupture  of  a  star, 
from  which  meteors  are  derived."  The  author  starts  with  the 
assumption  that  meteors  have  been  produced  by  the  rupture  of  a 
world,  basing  this  assumption  upon  the  arguments  he  has  stated  in 
previous  papers.  He  discards  altogether  Sir  W.  Thomson's  idea  of  a 
collision  between  two  worlds,  but  works  out  a  conclusion  quite  as 
melancholy. 

He  begins,  like  most  other  builders  of  cosmical  theories,  with  the 
hypothesis  that  this  and  all  the  other  worlds  of  space  began  their 
existence  in  a  condition  of  nebulous  infancy  ;  that  they  gradually 
condensed  into  molten  liquids,  and  then  cooled  down  till  they 
obtained  a  thin  outside  crust  of  solid  matter,  resting  upon  a  molten 
globe  within  ;  that  this  crust  then  gradually  thickened  as  the  world 
grew  older  and  cooled  down  by  radiation.  I  will  not  stop  to  discuss 
this  nebular  and  cooling-down  hypothesis  at  present,  though  it  is  but 
fair  to  state  that  "  I  don't  believe  a  bit  of  it." 

Taking  all  this  for  granted— a  considerable  assumption — M.  St. 
Meunier  reasons  very  ably  upon  what  must  follow  if  we  further 
assume  that  each  world  is  somehow  supplied  with  air  and  water,  and 
that  the  atmosphere  and  the  ocean  of  each  world  are  limited  and  un- 
connected with  those  of  any  other  world,  or  with  any  general  inter- 
stellar medium. 

What,  then,  will  happen  as  worlds  grow  old  ?  As  they  cool  down, 
they  must  contract  ;  the  liquid  inside  can  manage  this  without  any 
inconvenience  to  itself,  but  not  so  with  the  outer  spherical  shell  of 
solid  matter.  As  the  inner  or  hotter  part  of  this  contracts,  the  cool 
outside  must  crumple  up  in  order  to  follow  it,  and  thus  mountain 
chains  and  great  valleys,  lesser  hills  and  dales,  besides  faults  and 
slips,  dykes,  earthquakes,  volcanoes,  etc.,  are  explained. 

According  to  M.  St.  Meunier,  the  moon  has  reached  a  more  ad- 
vanced period  of  cosmical  existence  than  the  earth.  She  is  our 
senior  ;  and  like  the  old  man  who  shows  his  gray  hairs  and  tottering 
limbs  to  inconsiderate  youth,  she  shines  a  warning  upon  our  gay 
young  world,  telling  her  that — 

Let  her  paint  an  Inch  thick,  to  this  favor  she  must  come 

— that  the  air  and  ocean  must  pass  away,  that  all  the  living  creatures 
of  the  earth  must  perish,  and  the  desolation  shall  come  about  in  this 
wise. 

At  present,  the  interior  of  our  planet  is  described  as  a  molten  fluid, 
with  a  solid  crust  outside.  As  the  world  cools  down  with  age,  this 
crast  will  thicken  and  crack,  and  crack  again,  as  the  lower  part  con- 
tracts. This  will  form  rainures,  i.e  long  narrow  chasms,  of  vast 
depths,  which,  like  those  on  the  moon,  will  traverse,  without  devia- 
tion, the  mountains,  valleys,  plains,  and  ocean-beds  ;  the  waters  will 
fall  into  these,  and,  after  violent  catastrophes,  arising  from  their 
boiling  by  contact  with  the  hot  interior,  they  will  finally  disappear 
from  the  surface,  and  become  absorbed  in  the  pores  of  the  vastly 
thickened  earth-crust,  and  in  the  caverns,  cracks,  and  chasms  which 
the  rending  contraction  will  open  in  the  interior.  These  cavities  will 


262  SCIENCE   IN   SHORT   CHAPTERS. 

continue  to  increase,  will  become  of  huge  magnitude  \vhen  the  out- 
side crust  grows  thick  enough  to  form  its  own  supporting  arch,  for 
then  the  fused  interior  will  recede,  and  form  mighty  vaults  that  will 
engulf  not  the  waters  merely,  but  all  the  atmosphere  likewise. 

At  this  stage  the  earth,  according  to  M.  St.  Meunier,  will  be  a 
middle-aged  world  like  the  moon  ;  but  as  old  age  advances  the  con- 
traction of  the  fluid,  or  viscous  interior  beneath  the  outside  solid 
crust  will  continue,  and  the  rainures  will  extend  in  length  and  depth 
and  width,  as  he  maintains  they  are  now  growing  in  the  moon. 
This,  he  says,  must  continue  till  the  centre  solidifies,  and  then  these 
cracks  will  reach  that  centre,  and  the  world  will  be  split  through  in 
fragments  corresponding  to  the  different  rainures. 

Thus  we  shall  have  a  planet  composed  of  several  solid  fragments 
held  together  only  by  their  mutual  attractions,  but  the  rotary  move- 
ment of  these  will,  according  to  the  French  philosopher,  become  un- 
equal, as  *'  the  fragments  present  different  densities,  and  are  situated 
at  unequal  distances  from  the  centre  ;  some  will  be  accelerated, 
others  retarded  ;  they  will  rub  against  each  other,  and  grind  away 
those  portions  which  have  the  weakest  cohesion."  The  fragments 
thus  worn  off  will,  "  at  the  end  of  sufficient  time,  girdle  with  a  com- 
plete ring  the  central  star."  At  this  stage  the  fragments  become  real 
meteors,  and  then  perform  all  the  meteoric  functions  excepting  the 
seed-carry  ing  of  Sir  W.  Thomson. 

It  would  be  an  easy  task  to  demolish  these  speculations,  though 
not  within  the  space  of  one  of  my  letters.  A  glance  at  the  date  of 
this  paper,  and  the  state  of  Paris  and  the  French  mind  at  the  time, 
may,  to  some  extent,  explain  the  melancholy  relish  with  which  the 
Parisian  philosopher  works  out  his  doleful  speculations.  Had  the 
French  army  marched  vigorously  to  Berlin,  I  doubt  whether  this 
paper  would  ever  have  found  its  way  into  the  "  Comptes  Eendus. " 
After  the  fall  of  Paris,  and  the  wholesale  capitulation  of  the  French- 
armies,  it  was  but  natural  that  a  patriotic  Frenchman,  howsoever 
strong  his  philosophy,  should  speculate  on  the  collapse  of  all  the 
stars,  and  the  general Vinding-up  of  the  universe. 


CHAPTER  XXXV. 

THE   DYING   TKEES   IN"  KENSINGTON   GAEDENS. 

A  GKEAT  many  trees  have  lately  been  cut  down  in  Kensington  Gar- 
dens, and  the  subject  was  brought  before  the  House  of  Commons,  at 
the  latter  part  of  its  last  session.  In  reply  to  Mr.  Ritchie's  question, 
Mr.  Adam,  the  then  First  Commissioner  of  Works,  made  explanations 
which,  so  far  as  they  go,  are  satisfactory — but  the  distance  is  very 
small.  He  states  that  all  who  have  watched  the  trees  must  have  seen 
that  their  decay  "  has  become  rapid  and  decided  in  the  last  two 
years, "  that  when  the  vote  for  the  parks  came  on  many  "  were  either 
dead  or  hopelessly  dying, "  that  in  the  more  thickly  planted  portions 
of  the  gardens  the  trees  were  dead  and  dying  by  hundreds,  owing  to 
the  impoverished  soil  and  the  tenible  neglect  of  timely  thinning  fift~ 
or  sixty  years  ago. 


THE    DYIKG   TREES   I2S"   KEis'SIis'GTOK   GARDENS.        263 

Knowing  the  sensitiveness  of  the  public  regarding  tree-cutting,  Mr. 
Adam  obtained  the  co-operation  of  a  committee  of  experts,  consisting 
of  Sir  Joseph  Hooker,  Mr.  Clutton,  and  Mr.  Thomas,  "  so  distin- 
guished as  a  landscape  gardener,"  and  the  late  First  Commissioner 
of  Works.  They  had  several  meetings,  and,  as  Mr.  Adam  informs 
us,  "  the  result  has  been  a  unanimous  resolution  that  we  ought  to 
proceed  at  once  to  clear  away  the  dead  and  dying  trees."  This  is 
being  done  to  the  extent  of  "an  absolute  clearance"  in  some  places, 
and  the  removal  of  numerous  trees  all  over  the  gardens.  We  are 
further  told  that  "  the  spaces  cleared  will  either  be  trenched, 
drained,  and  replanted,  or  will  be  left  open,  as  may  appear  best." 
Mr.  Adam  adds  that  "  the  utmost  care  is  being  used  in  the  work  ; 
that  not  a  tree  is  being  cut  that  can  properly  be  spared  ;  and  that 
every  effort  will  be  made  to  restore  life  to  the  distinguished  trees 
that  are  dying." 

I  have  watched  the  proceedings  in  Kensington  Gardens  and  also 
in  Bushey  Park,  and  have  considerable  difficulty  in  describing  the 
agricultural  vandalism  there  witnessed,  and  expressing  my  opinion 
on  it,  without  transgressing  the  bounds  of  conventional  courtesy 
toward  those  who  are  responsible.  I  do  not  refer  to  the  cutting  down 
of  the  dead  and  dying  trees,  but  to  the  proceedings  by  which  they 
have  been  officially  and  artificially  killed  by  those  who  ought  to  pos- 
sess sufficient  knowledge  of  agricultural  chemistry  to  understand  the 
necessary  consequences  of  their  conduct. 

About  forty  years  have  elapsed  since  Liebig  taught  to  all  who  were 
able  and 'willing  to  learn,  that  trees  and  other  vegetables  are  com- 
posed of  two  classes  of  material  :  1st,  the  carbon  and  elements  of 
water  derived  from  air  and  rain;  and  2d,  the  nitrogenous  and  incom- 
bustible saline  compounds  derived  from  the  soil.  The  possible 
atmospheric  origin  of  some  of  the  nitrogen  is  still  under  debate,  but 
there  is  no  doubt  that  all  which  remains  behind  as  incombustible 
ash,  when  we  burn  a  leaf,  is  so  much  matter  taken  out  of  the  soil. 
Every  scientific  agriculturist  knows  that  certain  crops  take  away  cer- 
tain constituents  from  the  soil,  and  that  if  this  particular  cropping 
continues  without  a  replacing  of  those  particular  constituents  of  fer- 
tility, the  soil  must  become  barren  in  reference  to  the  crop  in  ques. 
tion,  though  other  crops  demanding  different  food  may  still  grow 
upon  it.  The  agricultural  vandalism  that  I  have  watched  with  so 
much  vexation  is  the  practice  of  annually  raking  and  sweeping  to- 
gether the  fallen  leaves,  collecting  them  in  barrows  and  carts,  and  then 
carrying  them  quite  away  from  the  soil  in  which  the  trees  are  grow- 
ing, or  should  grow.  I  have  inquired  of  the  men  thus  employed 
whether  they  put  anything  on  the  ground  to  replace  these  leaves,  and 
they  have  not  merely  replied  in  the  negative,  but  have  been  evidently 
surprised  at  such  a  question  being  asked.  What  is  finally  done  with 
the  leaves  I  do  not  know  ;  they  may  be  used  for  the  flower-beds  or 
sold  to  outside  florists.  I  have  seen  a  large  heap  accumulated  near 
to  the  Bound  Pond. 

Now,  the  leaves  of  forest  trees  are  just  those  portions  containing 
the  largest  proportion  of  ash  ;  or,  otherwise  stated,  they  do  the  most 
in  exhausting  the  soil.  In  Epping  Forest,  in  the  New  Forest,  and 
other  forests  where  there  has  been  still  more  ' '  terrible  neglect  of 
timely  thinning,"  the  trees  continue  to  grow  vigorously,  and  have 
ttius  grown  for  centuries  ;  the  leaves  fall  on  the  soil  wherein  the 


2G4  SCIENCE   IN   SHORT   CHAPTERS. 

trees  grow,  and  thus  continually  return  to  it  all  they  have  taken 
away. 

They  do  something  besides  this.  During  the  winter  they  grad- 
ually decay.  This  decay  is  a  process  of  slow  combustion,  giving  out 
just  as  much  heat  as  though  all  the  leaves  were  gathered  together  and 
used  as  fuel  for  a  bonfire  ;  but  the  heat  in  the  course  of  natural 
decay  is  gradually  given  out  just  when  and  where  it  is  wanted,  r,nd 
the  coating  of  leaves,  moreover,  forms  a  protecting  winter  jacket  to 
the  soil. 

I  am  aware  that  the  plea  for  this  sweeping-up  of  leaves  is  the  de- 
mand for  tidiness  ;  that  people  with  thin  shoes  might  wet  their  feet 
if  they  walked  through  a  stratum  of  fallen  leaves.  The  reply  to  this 
is,  that  all  reasonable  demands  of  this  class  would  be  satisfied  by 
clearing  the  foot-paths,  from  which  nobody  should  deviate  in  ihe 
winter  time.  Before  the  season  for  strolling  in  the  grass  returns, 
Nature  will  have  disposed  of  the  fallen  leaves.  A  partial  remedy 
may  be  applied  by  burning  the  leaves,  then  carefully  distributing 
their  ashes  ;  but  this  is  after  all  a  clumsy  imitation  cf  the  natural 
slow  combustion  above  described,  and  is  wasteful  of  the  ammoniacal 
gaits  as  well  as  of  the  heat.  The  avenues  of  Bushey  Park  are  not 
going  so  rapidly  as  the  old  sylvan  glories  of  Kensington  Gardens, 
though  the  same  robbery  of  the  soil  is  practised  in  both  places.  I 
have  a  theory  of  my  own  in  explanation  of  the  difference,  viz.  that 
the  cloud  of  dust  that  may  be  seen  blowing  from  the  roadway  as  the 
vehicles  drive  along  the  Chestnut  Avenue  of  Bushey  Park,  settles 
down  on  one  side  or  the  other  and  supplies  material  which  to  some 
extent,  but  not  sufficiently,  compensates  for  the  leaf-robbery. 

The  First  Commissioner  speaks  of  efforts  being  made  to  restore 
life  to  the  distinguished  trees  that  are  dying.  Let  us  hope  that  these 
include  a  restoration  to  the  soil  of  those  particular  salts  that  have  for 
some  years  past  been  annually  carted  away  from  it  in  the  form  of 
dead  leaves,  and  that  this  is  being  done  not  only  around  the  "  distin- 
guished "  trees,  but  throughout  the  gardens. 

Any  competent  analytical  chemist  may  supply  Mr.  Adam  with  a 
statement  of  what  are  "these  particular  salts.  This  information  is 
obtainable  by  simply  burning  an  average  sample  of  the  leaves  and 
analyzing  their  ashes. 

While  on  this  subject  I  may  add  a  few  words  on  another  that  is 
closely  connected  with  it.  In  some  parts  of  the  parks  gardeners  may 
be  seen  more  or  less  energetically  occupied  in  pushing  and  pulling 
effective  mowing-machines,  and  carrying  away  the  grass  which  is 
thus  cut.  This  produces  the  justly  admired  result  of  a  beautiful 
velvet  lawn  ;  but  unless  the  continuous  exhaustion  of  the  soil  is 
compensated,  a  few  years  of  such  cropping  will  starve  it.  This  sub- 
ject is  now  so  well  -understood  by  all  educated  gardeners,  that  it 
should  be  impossible  to  suppose  it  to  be  overlooked  in  our  parks,  as 
it  is  so  frequently  in  domestic  gardening.  Many  a  lawn  that  a  few 
years  ago  was  the  pride  of  its  owner  is  now  becoming  as  bald  as  the 
head  of  the  faithful,  "  practical,"  and  obstinate  old  gardener  who  so 
heartily  despises  the  "  fads"  of  scientific  theorists. 

When  natural  mowing-machines  are  used,  i.e.  cattle  and  sheep, 
their  droppings  restore  all  that  they  take  away  from  the  soil,  minus 
the  salts  contained  in  their  own  flesh,  or  the  milk  that  may  be 
removed.  An  interesting  problem  has  been  for  some  time  past 


OLEAGIKOUS   PRODUCTS   OF  THAMES   MUD.  265 

under  the  consideration  of  the  more  scientific  of  the  Swiss  agricul- 
turists. Prom  the  mountain  pasturages  only  milk  is  taken  away,  but 
this  milk  contains  a  certain  quantity  of  phosphates,  the  restoration 
of  which  must  be  effected  sooner  or  later,  or  the  produce  will  be  cut 
off,  especially  now  that  so  much  condensed  milk  is  exported. 

The  wondrously  rich  soil  of  some  parts  of  Virginia  has  been  ex- 
hausted by  unrequited  tobacco  crops.  The  quantity  of  ash  dis- 
played on  the  burnt  end  of  a  cigar  demonstrates  the  exhausting  char- 
acter of  tobacco  crops.  That  which  the  air  and  water  supplied  to  the 
plant  is  returned  as  invisible  gases  during  combustion,  but  all  the 
ash  that  remains  represents  what  the  leaves  have  taken  from  the  soil, 
and  what  should  be  restored  in  order  to  sustain  its  pristine  fertility. 

The  West  India  Islands  have  similarly  suffered  to  a  very  serious 
extent  on  account  of  the  former  ignorance  of  the  sugar  planters,  who 
used  the  canes  as  fuel  in  boiling  down  the  syrup,  and  allowed  the 
ashes  of  those  canes  to  be  washed  into  the  sea.  They  were  ignorant 
of  the  fact  that  pure  sugar  may  be  taken  away  in  unlimited  quanti- 
ties without  any  impoverishment  of  the  land,  seeing  that  it  is  com- 
posed merely  of  carbon  and  the  elements  of  water,  all  derivable  from 
air  and  rain.  All  that  is  needed  to  maintain  the  perennial  fertility 
of  a  sugar  plantation  is  to  restore  the  stems  and  leaves  of  the  cane, 
or  carefully  to  distribute  their  ashes. 

The  relation  of  these  to  the  soil  of  the  sugar  plantations  is  pre- 
cisely the  same  as  that  of  the  leaves  of  the  trees  to  the  soil  of  Ken- 
sington Gardens,  and  the  reckless  removal  of  either  must  produce 
the  same  disastrous  consequences. 


CHAPTEK  XXXVI. 

THE   OLEAGINOUS   PEODUCTS    OP  THAMES   MUD  :    WHEEE   THEY  COME  FROM 
AND  WHEBE   THEY  GO. 

ONCE  upon  a  time— and  not  a  very  long  time  since— a  French 
chemist  left  the  land  of  superexcellence,  and  crossed  to  the  shores  of 
foggy  Albion.  He  proceeded  to  Yorkshire,  his  object  being  to  make 
his  fortune.  He  was  so  presumptuous  as  to  believe  that  he  might  do 
this  by  picking  up  something  which  Yorkshireinen  threw  away. 
That  something  was  soapsuds.  His  chemistry  taught  him  that  soap 
is  a  compound  of  fat  and  alkali,  and  that  if  a  stronger  acid  than  that 
belonging  to  the  fat  is  added  to  soapsuds,  the  stronger  acid  will  coin- 
bine  with  the  alkali  and  release  the  fat,  the  which  fat  thus  liberated 
will  float  upon  the  surface  of  the  liquid,  and  may  then  be  easily 
skimmed  off,  melted  together,  and  sold  at  a  handsome  profit. 

But  why  leave  the  beautiful  France  and  desolate  himself  in  dreary 
Yorkshire  merely  to  do  this  ?  His  reason  was,  that  the  cloth  workers 
of  Yorkshire  use  tons  and  tons  of  soap  for  scouring  their  materials, 
and  throw  away  millions  of  gallons  of  soapsuds.  Besides  this,  there 
are  manufactories  of  sulphuric  acid  near  at  hand,  and  a  large  demand 
for  machinery  grease  just  thereabouts.  He  accordingly  bought  iron 
tanks,  and  erected  works  in  the  midst  of  the  busiest  centre  of  the 


266  SCIENCE   IX   SHORT   CHAPTERS. 

woollen  manufacture.  But  he  did  not  make  his  fortune  all  at  once. 
On  the  contrary,  he  failed  to  pay  expenses,  for  in  his  calculations  he 
had  omitted  to  allow  for  the  fact  that  the  soap  liquor  is  much  diluted 
and  therefore  he  must  carry  much  water  in  order  to  obtain  a  little 
fat.  This  cost  of  carriage  ruined  his  enterprise,  and  his  works  were 
offered  for  sale. 

The  purchaser  was  a  shrewd  Yorkshireman,  who  then  was  a  dealer 
in  second-hand  boilers,  tanks,  and  other  iron  wares.  When  he  was 
about  to  demolish  the  works,  the  Frenchman  took  him  into  confi- 
dence, and  told  the  story  of  his  failure.  The  Yorkshireman  said 
Jittle,  but  thought  much  ;  and  having  finally  assured  himself  that  the 
carriage  was  the  only  difficulty,  he  concluded,  after  the  manner  of 
Mahomet,  that  if  the  mountain  would  not  come  to  him,  he  might  go 
to  the  mountain  ;  and  then  made  an  offer  of  partnership  on  the  basis 
that  the  Frenchman  should  do  the  chemistry  of  the  work,  and  that  he 
(the  Yorkshireman)  should  do  the  rest. 

Accordingly,  he  went  to  the  works  around,  and  offered  to  contract 
for  the  purchase  of  all  their  soapsuds,  if  they  would  allow  him  to  put 
up  a  tank  or  two  on  their  premises.  This  he  did  ;  the  acid  was 
added,  the  fat  rose  to  the  surface,  was  skimmed  off,  and  carried,  loith- 
out  the  water,  to  the  central  works,  where  it  was  melted  down,  and, 
with  very  little  preparation,  was  converted  into  "  cold-neck, grease, " 
and  "  hot-neck  grease,"  and  used,  besides,  for  other  lubricating  pur- 
poses. The  Frenchman's  science  and  skill,  united  with  the  York- 
shireman's  practical  sagacity,  built  up  a  nourishing  business,  and  the 
grease  thus  made  is  still  in  great  demand  and  high  repute  for  lubri- 
cating the  rolling-mills  of  ironworks,  and  for  many  other  kinds  of 
machinery. 

My  readers  need  not  be  told  that  there  are  soapsuds  in  London  as 
well  as  in  Yorkshire,  and  they  also  know  that  the  London  soapsuds 
pass  down  the  drains  into  the  sewers.  I  may  tell  them  that  besides 
this  there  are  many  kinds  of  acids  also  passed  into  London  sewers, 
and  that  others  are  generated  by  the  decompositions  there  abound- 
ing. These  acids  do  the  Frenchman's  work  upon  the  London  soap- 
suds, but  the  separated  fat,  instead  of  rising  slowly  and  undisturbed 
to  form  a  film  upon  the  surface  of  the  water,  is  rolled  and  tumbled 
among  its  multifarious  companion  filth,  and  it  sticks  to  whatever  it 
may  find  congenial  to  itself.  Hairs,  rags,  wool,  ravellings  of  cotton, 
and  fibres  of  all  kinds  are  especially  fraternal  to  such  films  of  fat  :  they 
lick  it  up  and  stick  it  about  and  amid  themselves  ;  and  as  they  and 
the  fat  roll  and  tumble  along  the  sewers  together,  they  become  com- 
pounded and  shaped  into  unsavory  balls  that  are  finally  deposited  on 
the  banks  of  the  Thames,  and  quietly  repose  in  its  hospitable  mud. 

But  there  is  no  peace  even  there,  and  the  gentle  rest  of  the  fat 
nodules  is  of  short  duration.  The  mud-larks  are  down  upon  them, 
in  spite  of  all  their  burrowing  ;  they  are  gathered  up  and  melted 
down.  The  filthiest  of  their  associated  filth  is  thus  removed,  and 
then,  and  with  a  very  little  further  preparation,  they  appear  as  cakes 
of  dark-colored  hard  fat,  very  well  suited  for  lubricating  machinery, 
and  indifferently  fit  for  again  becoming  soap,  and  once  more  repeat- 
ing their  former  adventures. 

Those  gentlemen  of  the  British*  press  whose  brilliant  imagination 
supplies  the  public  with  their  intersessional  harvests  of  sensational 
adulteration  panics,  have  obtained  a  fertile  source  of  paragraphs  by 


LUMINOUS   PALST.  267 

co-operating  with  the  mud-larks  in  the  manufacture  of  butter  from 
Thames  inud. 

The  origin  of  these  stories  is  traceable  to  certain  officers  of  the 
Thames  police,  who,  having  on  board  some  of  these  gentlemen  of  the 
press  engaged  in  hunting  up  information  respecting  a  body  found  in 
the  river,  supplied  their  guests  with  a  little  supplementary  chaff  by 
showing  them  a  mud-lark's  gatherings,  and  telling  them  that  it  was 
raw  material  from  which  "  tine  Dorset"  is  produced.  A  communi- 
cation from  "  Our  Special  Correspondent"  on  the  manufacture  of 
butter  from  Thames  mud  accordingly  appeared  in  the  atrocity  column 
on  the  following  morning,  and  presently  "  went  the  round  of  the 
papers." 

Although  it  is  perfectly  possible  by  the  aid  of  modern  chemical 
skill  to  refine  even  such  filth  as  this,  and  to  churn  it  into  a  close 
resemblance  to  butter,  the  cost  of  doing  so  would  exceed  the  highest 
price  obtainable  for  the  finest  butter  that  comes  to  the  London 
market.  A  skilful  chemist  can  convert  all  the  cotton  fibres  that  are 
associated  with  this  sewage  fat  into  pure  sugar  or  sugar-candy,  .but 
the  manufacture  of  sweetmeats  from  Thames  mud  would  not  pay  any 
better  than  the  production  of  butter  from  the  same  source,  and  for 
the  same  reason. 

Mutton-suet,  shop-parings,  and  other  clean,  wholesome  fat  can  be 
bought  wholesale  for  less  than  fivepence  per  pound.  It  would  cost 
above  three  times  as  much  as  this  to  bring  the  fat  nodules  of  the 
Thames  mud  to  as  near  an  approach  to  butter  as  this  sort  of  fat. 
Therefore  the  Thames  mud-butter  material  would  be  three  times  as 
costly  as  that  obtainable  from  the  butcher,  While  the  supply  of 
mutton-suet  is  so  far  in  excess  of  the  butter-making  demand  that 
tons  of  it  are  annually  used  in  the  North  for  lubricating  machinery, 
we  need  not  fear  that  anything  less  objectionable — i.e.  more  costly 
to  purify— will  be  used  as  a  butter  substitute. 


CHAPTER   XXXVII. 

LUMINOUS   PAINT. 

THE  sun  is  evidently  going  out  of  fashion,  and  is  more  and  more 
excluded  from  "  good  society"  as  our  modern  substitute  for  civiliza- 
tion advances.  "  Serve  him  right !"  many  will  say  for  behaving  so 
badly  during  the  last  two  summers.  The  old  saw,  which  says  some- 
thing about  "  early  to  bed  and  early  to  rise"  is  forgotten  :  we  take 
"  luncheon1'  at  dinner  time,  dine  at  supper  time,  make  "morning" 
calls  and  go  to  "  morning"  concerts,  etc.  late  in  the  afternoon,  say 
"  Good  morning"  until  6  or  7  P.M.  ;  and  thus,  by  sleeping  through 
the  bright  hours  of  the  morning,  and  waking  up  fully  only  a  little 
before  sunset,  the  demand  for  artificial  light  becomes  almost  over- 
whelming. Not  only  do  we  require  this  during  a  longer  period  each 
day,  but  we  insist  upon  more  and  more,  and  still  more  yet,  during 
that  period. 

The  rushlight  of  our  forefathers  was  superseded  by  an  exotic  lux- 


268  SCIENCE   IX   SHORT   CHAPTERS. 

nry,  the  big-flame  candle  made  of  Knssian  tallow,  with  a  wick  of 
Transatlantic  cotton.  Presently  this  luxurious  innovation  was 
superseded  by  the  "  mould  candle  ;"  the  dip  was  consigned  to  the 
kitchen,  and  the  bloated  aristocrats  of  the  period  indulged  in  a  pair 
of  candlesticks,  alarming  their  grandmothers  by  the  extravagance  of 
burning  two  candles  on  one  table.  Presently  the  mould  candle  was 
snuffed  out  by  the  composite  ;  then  came  the  translucent  pearly  par- 
affine  candle,  gaslight,  solar  lamps,  moderator  lamps,  and  parafnne 
lamps.  Even  these,  with  their  brilliant  white  flame  from  a  single 
wick,  are  now  insufficient,  and  we  have  duplex  and  even  triplex 
wicks  to  satisfy  our  demand  for  glaring  mockeries  of  the  departed 
sun. 

Some  are  still  living  who  remember  the  oil  lamps  in  Cheapside  and 
Piccadilly,  and  the  excitement  caused  by  the  brilliancy  of  the  new 
gas  lamps  ;  but  now  we  are  dissatisfied  with  these,  and  demand 
electric  lights  for  common  thoroughfares,  or  some  extravagant  com- 
bination of  concentric  or  multiplex  gas-jets  to  rival  it. 

The  latest  novelty  is  a  device  to  render  darkness  visible  by  captur- 
ing the  sunbeams  during  the  day,  holding  them  as  prisoners  until 
after  sunset,  and  then  setting  them  free  in  the  night.  The  principle 
is  not  a  new  discovery  ;  the  novelty  lies  in  the  application  and  some 
improvements  of  detail.  In  the  "Boy's  Own  Book,"  or  "Endless 
Amusement,"  of  thirty  or  forty  years  ago,  are  descriptions  of  "  Can- 
tm's  phosphorus,"  or  "  solar  phosphori,"  and  recipes  for  making 
t'lem.  Burned  oyster-shells  or  oyster-shells  burned  with  sulphur, 
was  one  of  these. 

Various  other  methods  of  effecting  combination  between  lime  or 
baryta  with  sulphur  are  described  in  old  books,  the  result  being  the 
formation  of  more  or  less  of  what  modern  chemists  call  calcium  sul- 
phide and  barium  sulphide  (or  otherwise  sulphide  of  calcium  or  sul- 
phide of  barium).  These  compounds,  when  exposed  to  the  sun,  are 
mysteriously  acted  upon  by  the  solar  rays,  and  put  into  such  a  con- 
di:ion  that  their  atoms  or  molecules,  or  whatever  else  constitutes 
their  substance,  are  set  in  motion — in  that  sort  of  motion  which  com- 
municates to  the  surrounding  medium  the  wavy  tremor  which 
agitates  our  optic  nerve  and  produces  the  sensation  of  light. 

Until  lately,  this  property  has  served  no  other  purpose  than  puz- 
zling philosophers,  and  amusing  that  class  of  boys  who  burn  their 
fingers,  spoil  their  clothes,  and  make  holes  in  their  mothers'  table- 
covers,  with  sulphuric  acid,  nitric  acid,  and  other  noxious  chemicals. 
The  first  idea  of  turning  it  to  practical  account  was  that  of  making  a 
sort  of  enamel  of  one  or  the  other  of  these  sulphides,  and  using  it  as 
a  coating  for  clock-faces.  A  surface  thus  coated  and  exposed  to  the 
light  during  the  day  becomes  faintly  luminous  at  night. 

Anybody  desirous  of  seeing  the  sort  of  light  which  it  emits  may 
do  so  very  easily  by  purchasing  an  unwashed  smelt  from  the  fish- 
monger, and  allowing  it  to  dry  with  its  natural  slime  upon  it,  then 
loeking  at  it  in  the  dark.  A  sole  or  almost  any  other  fish  will  answer 
the  purpose,  but  I  name  the  smelt  from  having  found  it  the  most 
reliable  in  the  course  of  my  own  experiments.  It  emits  a  dull, 
ghostly  light,  with  very  little  penetrating  power,  which  shows  the 
shape  of  the  fish,  but  casts  no  perceptible  light  on  objects  around. 

Thus  the  phosphorescent  parish-clock  face,  with  non-phosphores- 
cent figures  and  hands,  would  look  like  a  pale  ghost  of  the  rncon  with 


LUMINOUS   PAINT.  2G9 

dark  figures  round  it,  and  dark  hands  stretching  across,  by  which  the 
time  of  the  night  might  possibly  be  discovered  there  or  thereabouts. 
This  invention  has  already  appeared  in  a  great  many  paragraphs,  but, 
hitherto,  upon  very  few  clock-faces. 

Recently  it  has  assumed  a  more  ambitious  form — patented,  of 
course.  The  patentees  claim  an  improved  phosphorescent  powder, 
which  is  capable  of  being  worked  up  with  the  medium  of  paints  and 
varnishes,  and  thus  applied,  not  merely  to  clock-faces,  but  to  the 
whole  of  the  walls  and  ceilings  of  any  apartment.  In  this  case  the 
faintness  of  the  light  will  be  in  some  degree  compensated  by  the  ex- 
tent of  phosphorescent  surface,  and  it  is  just  possible  that  the  sum 
total  of  the  light  emitted  from  walls  and  ceiling  may  be  nearly  equal 
to  that  of  one  mould  candle.  If  so,  it  will  have  some  value  as  a 
means  of  lighting  powder  magazines  and  places  for  storage  of  inflam- 
mable compounds.  It  is  stated  that  one  of  the  London  dock  com- 
panies is  about  to  use  it  for  its  spirit  vaults  ;  also  that  the  Admiralty 
has  already  tried  the  paint  at  Whitehall,  and  has  ordered  two  com- 
partments of  the  Coinus  to  be  painted  with  it,  in  order  to  test  its 
capability  of  lighting  the  dark  regions  of  ironclad  ships. 

This  application  can,  however,  only  be  limited  to  those  parts 
which  receive  a  fair  amount  of  light  during  the  day,  for  unless  the 
composition  first  receives  light,  it  is  not  able  afterward  to  emit  it, 
and  this  emission  or  phosphorescence  only  continues  a  few  hours 
after  the  daylight  has  passed  away  ;  five  or  six  hours  is  the  time 
stated. 

A  theatrical  manager  is  said  to  be  negotiating  for  the  exclusive 
right  to  employ  this  weird  illumination  for  scenic  purposes.  The 
sepulchre  scene  in  tiobert  le  Diable,  or  the  incantation  in  Der  Frei- 
schutz,  or  21ie  Sorcerer,  might  be  made  especially  effective  by  its  ghostly 
aid.  The  name-plates  of  streets,  and  buoys  at  sea  might  be  advan- 
tageously coated  with  such  a  composition  ;  and  many  other  uses  sug- 
gest themselves. 

There  are  rival  inventors,  as  a  matter  of  course.  The  French  pat- 
entees claim  the  use  of  cuttle-fish  bones,  various  sea-shells,  etc., 
mixed  with  pure  lime,  sulphur,  and  calcined  sea-salt,  besides  sul- 
phides of  calcium,  barium,  strontium,  uranium,  magnesium,  or 
aluminium.  They  also  add  phosphorus  itself,  though  for  what  pur- 
pose is  questionable,  seeing  that  this  substance  is  only  luminous 
during  the  course  of  its  oxidation  or  slow  combustion,  and  after  this 
has  ended  the  resultant  phosphoric  acid  is  no  more  luminous  than 
linseed  oil  or  turpentine.  An  admixture  of  phosphorus  might  tempo  • 
rarily  increase  the  luminosity  of  a  sample,  but  any  conclusions  based 
upon  this  would  be  quite  delusive.  They  also  assert  that  electrical 
discharges  passed  through  the  paint  increase  its  luminosity. 
According  to  some  enthusiasts,  electricity  is  to  do  everything  ;  but 
these  ladies  and  gentlemen  omit  to  calculate  the  cost  of  rousing  and 
feeding  this  omnipotent  giant.  In  this  case  electrical  machinery  for 
stimulating  the  paint  for  anything  outside  of  lecture-table  experi- 
ments or  theatrical  and  other  sensational  displays,  would  be  a  com  • 
mercial  absurdity. 

The  Americans,  of  course,  are  reinventing  in  this  direction,  but 
Mr.  Edison  has  not  yet  appeared  on  the  luminous-paint  scene.  If 
he  does  we  shall  doubtless  hear  of  something  very  brilliant,  even 
though  we  never  see  it.  In  the  mean  time  wo  may  safely  hope  that 


270  SCIENCE   IN   SHORT   CHAPTERS. 

this  application  of  an  old  scientific  plaything  to  useful  purposes  may 
become  of  considerable  utility,  as  it  evidently  opens  a  wide  field  for 
further  investigation  and  progressive  improvement,  by  the  applica- 
tion of  the  enlarged  powers  which  modern  science  places  at  the  dis- 
posal of  ingenious  inventors.  "We  hope,  for  the  sake  of  all  con- 
cerned, that  it  will  not  fall  into  the  hands  of  professional  prospectus- 
manufacturers  and  joint-stock-company-mongers,  and  that  the  story 
of  its  triumphs  will  be  told  without  any  newspaper  exaggerations. 

Since  the  above  was  written— in  February,  1880 — I  have  tested  this 
luminous  paint  (Balmain's  patent).  Practically,  I  find  it  unsatisfac- 
tory. In  the  first  place,  its  endurance  is  far  shorter  than  is  stated. 
It  begins  to  fade  almost  immediately  the  light  is  withdrawn,  and  in 
the  coiirse  of  an  hour  or  two  it  is,  for  all  practical  use — though  not 
absolutely — extinguished.  Besides  this  it  emits  a  very  unpleasant 
odor  painfully  resembling  sewage  and  sulphuretted  hydrogen.  This 
is  doubtless  due  to  the  sulphur  compound,  but  is,  I  have  no  doubt, 
quite  harmless  in  spite  of  its  suggestions. 


CHAPTER  XXXVIII. 

THE  OEIGIN  AND  PEOBABLE  DUEATION  OF  PETEOLEUM. 

IN  spite  of  the  enormous  quantities  of  mineral  oil  that  are  continu- 
ously drawn  from  the  earth,  and  the  many  places  from  which  it  may 
thus  be  drawn,  geologists  are  still  puzzled  to  account  for  it.  If  it 
were  commonly  associated  with  coal  the  problem  of  its  origin  would 
be  solved  at  once.  We  should  then  be  satisfied'  that  natural  mineral 
oil  is  produced  in  the  same  manner  as  the  artificial  product— i.e.  by 
the  heating  and  consequent  distillation  of  certain  kinds  of  coal  or  of 
bituminous  shales  ;  but,  as  a  matter  of  fact,  it  is  but  rarely  that  petro- 
leum is  found  in  the  midst  of  coal  seams,  though  it  is  sometimes  so 
found. 

I  visited,  some  years  ago,  a  coal-mine  in  Shropshire,  known  as 
"the  tarry  pit,"  thus  named  on  account  of  the  large  quantity  of 
crude  mineral  oil  of  a  rather  coarse  quality  that  exuded  from  the 
strata  pierced  by  the  shaft.  It  ran  down  the  sides  of  the  shaft,  filled 
the  "  sumph"  (i.e.  the  well  at  the  bottom  of  the  shaft  in  which  the 
water  draining  from  the  mine  should  accumulate  for  pumping),  and 
annoyed  the  colliers  so  seriously  lhat  they  refused  to  work  in  the 
mine  unless  the  nuisance  were  abolished.  It  was  abolished  by  "  tub- 
bing" the  shaft  with  an  oil-proof  lining  built  round  that  part  from 
which  the  oil  issued.  The  "tar,"  as  the  crude  oil  was  called,  was 
then  pumped  out  of  the  sumph,  and  formed  a  pool  which  has  since 
been  filled  up  by  the  debris  of  the  ordinary  mine  workings. 

A  piiblican  in  the  Black  Country  of  South  Staffordshire  discovered 
an  issue  of  inflammable  vapor  in  his  dellar,  collected  it  by  thrusting 
a  pipe  into  the  ground,  and  used  it  for  lighting  and  warming  pur- 
poses, as  well  as  an  attraction  to  customers. 

These  and  other  cases  that  might  be  cited,  although  exceptional, 
are  of  some  value  in  helping  us  to  form  a  simple  and  rational  theory 


THE   ORIGIN   AND    DURATION    OF   PETROLEUM.        271 

of  the  origin  of  this  important  natural  product.  They  prove  that 
mineral  oil  may  be  produced  in  connection  with  coal  seams  and  ap- 
parently from  the  coal  itself.  A  sound  theory  of  the  origin  of  petro- 
leum is  of  practical  as  well  as  theoretical  value,  inasmuch  as  the  very 
practical  question  of  the  probable  permanency  of  supply  depends 
entirely  on  the  nature  of  the  origin  of  that  supply.  Some  very  odd 
theories  have  been  put  forth,  especially  in  America. 

Seeing  that  petroleum  is  commonly  found  associated  with  sand- 
stone and  limestone,  especially  in  cavities  of  the  latter,  it  has  been 
supposed  that  these  minerals  somehow  produce  it.  Turning  back  to 
the  Grocer  for  April  18th,  1872,  I  find  some  speculations  of  this  kind 
quoted  from  the  Petroleum  Monthly.  The  writer  sets  aside  altogether, 
as  an  antiquated  and  exploded  fallacy,  the  idea  that  petroleum  is  pro- 
duced from  coal,  and  maintains  "  that  petroleum  is  mainly  produced 
from,  or  generated  through,  limestone,"  and  argues  that  the  genera- 
tion of  petroleum  by  such  rocks  is  a  continuous  process,  from  the 
fact  that  exhausted  wells  have  recovered  after  being  abandoned,  his 
explanation  being  "  that  the  formerly  abandoned  territory  was  given 
up  because  the  machinery  for  extracting  petroleum  from  the  earth 
exceeded  in  its  power  of  exhausting  the  fluid  the  generative  powers 
by  which  it  is  produced  ;"  these  generative  powers  somehow  resid- 
ing in  the  limestone  and  sandstone,  but  how  is  not  specified. 

Some  writers  have,  however,  gone  a  little  further  toward  answering 
the  question  of  how  limestone  may  generate  petroleum.  They  have 
pointed  to  the  fossilized  remains  of  animals,  their  shells,  etc.,  exist- 
ing in  the  limestone,  and  have  supposed  that  the  animal  matter  has 
been  distilled,  and  has  thus  formed  the  oil. 

If  such  a  process  could  be  imitated  artificially  by  distilling  some  of 
the  later  deposits  of  similar  fossil  character  this  theory  would  have  a 
better  basis,  or  even  if  a  collection  of  oysters,  mussels,  or  any  other 
animal  matters  could  by  distillation  be  shown  to  produce  an  oil  simi- 
lar to  petroleum. 

The  contrary  is  the  case.  We  may  obtain  oil  from  such  material, 
but  it  is  utterly  different  from  any  kind  of  mineral  oil,  while,  on  the 
other  hand,  by  distilling  natural  bituminous  shales,  or  cannel  coal,  or 
peat,  we  obtain  a  crude  oil  almost  identical  with  natural  petroleum, 
and  the  little  difference  between  the  two  is  perfectly  accounted  for 
by  the  greater  rapidity  of  our  methods  of  distillation  as  compared 
with  the  slow  natural  process.  We  may  go  on  approximating  more 
and  more  nearly  to  the  natural  petroleum  by  distilling  more  and 
more  slowly.  As  it  is,  the  refined  products  of  the  natural  and  artifi- 
cial oil  which  is  commercially  distilled  in  Scotland,  are  scarcely  dis- 
tinguishable— some  of  them  are  not  at  all  distinguishable — the  solid 
paraffme,  for  example.  I  now  offer  my  own  theory  of  the  origin  of  oil 
springs. 

To  render  this  the  more  intelligible,  let  us  first  consider  the  origin 
of  ordinary  water  springs.  St.  Winifred's  Well,  at  Holywell,  in  Flint- 
shire, may  be  taken  as  an  example,  not  merely  on  account  of  its  mag- 
nitude, but  because  it  is  quite  typical,  and  is  connected  with  lime- 
stone and  sandstone  in  about  the  same  manner  as  are  the  petroleum 
wells  of  Pennsylvania. 

Here  we  have  a  wondrous  uprush  of  water  just  between  the  sand- 
stone and  mountain  limestone  rocks,  which  amounts  to  above  twenty 
tons  per  minute,  and  flows  down  to  the  Dee,  a  small  river  turning 


272  SCIENCE   IN   SHORT   CHAPTERS. 

several  water-mills.  It  is  certain  that  all  this  water  is  not  generated 
either  by  the  limestone  or  the  sandstone  from  which  it  issues,  nor 
can  it  be  all  "  generated"  on  the  spot.  The  true  explanation  of  its 
origin  is  simple  enough. 

The  mountain  limestone  underlies  the  coal-measures  and  crops  up 
obliquely  at  Holy  well  ;  against  this  oblique  subterranean  wall  of 
compact  rock  impermeable  to  water,  abuts  a  great  face  of  down- 
sloping  strata  of  porous  sandstone  and  porous  shales.  These  porous 
rocks  receive  the  rain  which  falls  on  the  slopes  of  the  Hope  Mountain 
and  other  hills  which  they  form  ;  this  water  sinks  into  the  millstone 
grit  of  these  hills  and  percolates  downward  until  it  reaches  the  lime- 
stone barrier,  into  which  it  cannot  penetrate. 

It  here  accumulates  as  a  subterranean  reservoir  which  finds  an  out- 
let at  a  convenient  natural  fissure,  and,  as  the  percolation  is  contin- 
uous, the  spring  is  a  constant  one.  Some  of  the  water  travels  many 
miles  underground  before  it  thus  escapes.  Hundreds  of  other  simi- 
lar instances  might  be  quoted,  the  above  being  the  common  history 
of  springs  which  start  up  whenever  the  underground  waters  that  flow 
through  porous  rocks  or  soil  meet  with  compact  rocks  or  impermeable 
clay,  and  thus,  being  able  to  proceed  no  further  downward,  accumu- 
late and  produce  an  overflow  which  we  call  a  "  spring." 

If  water  can  thus  travel  underground,  why  not  oil  ? 

Although  the  oil  springs  or  oil  wells  are  not  immediately  above  or 
below  coal  seams,  they  are  all  within  "  measurable  distance"  of  great 
coal  formations — the  oil  territory  of  Pennsylvania  is,  in  fact,  sur- 
rounded by  coal,  some  of  it  anthracite,  which  is  really  a  coke,  such 
as  would  be  produced  if  we  artificially  distilled  the  hydrocarbons 
from  coal,  and  then  compressed  the  residue,  as  the  anthracite  has 
certainly  been  pressed  by  the  strata  resting  upon  it. 

The  rocks  in  immediate  contact  and  proximity  to  coal  seams — "the 
coal-measures,"  as  they  are  called— are  mostly  porous,  some  of  them 
very  porous,  and  thus  if  at  any  period  of  the  earth's  long  history  a 
seam  of  coal  became  heated,  as  we  know  so  many  strata  are,  and 
have  been  heated,  a  mineral  oil  would  certainly  be  formed,  v/ould 
first  permeate  the  porous  rocks  as  vapor,  then  be  condensed  and 
make  its  way  through  them,  following  their  "  dip"  or  inclination 
until  it  reached  a  barrier  such  as  the  limestone  forms. 

It  would  thus  in  after-ages  be  found,  not  among  the  coal  where  it 
was  formed,  but  at  the  limestone  or  other  impermeable  rock  by  which 
its  further  percolation  was  arrested. 

This  is  just  where  it  actually  is  found. 

Limestone,  although  not  porous  like  shales  and  sandstones,  is 
specially  well  adapted  for  storing  large  subterranean  accumulations, 
on  account  of  the  great  cavities  to  which  it  is  liable.  Nearly  all  the 
caverns  in  this  country,  in  Ireland  where  they  abound,  in  America, 
and  other  parts  of  the  world  are  in  limestone  rocks  ;  they  are  espe- 
cially abundant  in  the  "  carboniferous  limestone"  which  underlies  the 
coal-measures,  and  this  is  explained  by  the  fact  that  limestone  may 
be  dissolved  by  rain-water  that  has  oozed  through  vegetable  soil  or 
has  soaked  fallen  leaves  or  other  vegetable  matter,  and  thereby  be- 
come saturated  with  carbonic  acid. 

Where  the  petroleum  finds  a  crevice  leading  to  such  cavities  it 
must  creep  through  it  and  fill  the  space,  thereby  forming  one  of  the 
underground  reservoirs  supplying  those  pumping  wells  that  have 


THE   ORIGIN   AND   DURATION   OF   PETROLEUM.        273 

yielded  such  abundance  for  a  while  and  then  become  dry.  But  if 
this  theory  is  correct  it  does  not  follow  thab  the  drying  of  such  a  well 
proves  a  final  stoppage  of  the  supply,  for  if  the  cavity  and  crevice  are 
left,  more  oil  may  ooze  into  the  crevice  and  flow  into  the  cavity,  and 
this  may  continue  again  and  again  throughout  the  whole  oil  district 
so  long  as  the  surrounding  feeders  of  permeable  strata  continue  satu- 
rated, or  nearly  so.  The  magnitude  of  these  feeding  grounds  may 
far  exceed  that  of  the  district  wherein  the  springs  occur,  or  where 
profitable  wells  may  be  sunk,  seeing  that  the  localizing  of  profitable 
supply  depends  mainly  on  the  stoppage  of  further  oozing  away  by 
the  action  of  the  impermeable  barrier. 

A  well  sunk  into  the  oozing  strata  itself  would  receive  a  very  small 
quantity,  only  that  which,  in  the  course  of  its  passage  came  upon  the 
well  sides,  while  at  the  junction  between  the  permeable  and  imper- 
meable rocks  the  accumulation  may  include  all  that  reached  the 
whole  surface  of  such  junction  or  contact — many  square  miles. 

To  test  this  theory  thoroughly  it  would  be  necessary  to  make  bor- 
ings, not  merely  at  the  wells,  but  in  their  neighborhood,  where  the 
porous  rocks  dip  toward  the  limestone,  and  to  bring  up  sample  cores 
of  these  porous  rocks,  and  carefully  examine  them.  Dr.  Sterry  Hunt 
has  done  this  in  the  oil-yielding  limestone  rocks  of  Chicago,  but  not 
in  those  of  the  nearest  coal-measures. 

As  the  oil  industry  of  America  is  of  such  great  national  impor- 
tance, an  investigation  of  this  kind  is  worthy  of  the  energies  of  the 
American  Government  geologists.  It  would  throw  much  light  on  the 
whole  subject,  and  supply  data  from  which  the  probable  duration  of 
the  oil  supply  might  be  approximately  calculated. 

Such  an  investigation  might  even  do  more  than  this.  By  proving 
the  geological  conditions  upon  which  depend  the  production  of  petro- 
leum springs,  new  s.ources  may  be  discovered,  just  as  new  coal-seams 
have  been  discovered,  in  accordance  with  geological  prediction,  or  as 
the  practical  discovery  of  the  Australian  gold-fields  was  so  long  pre- 
ceded by  Sir  Roderick  Murchison's  theoretical  announcement  of 
their  probable  existence. 

When  the  "kerosene  wells"  were  first  struck,  the  speculations 
concerning  their  probable  permanency  were  wild  and  various.  Some 
maintained  that  it  was  but  a  spurt,  a  freak  of  nature  limited  to  a 
narrow  locality,  and  would  soon  be  over  ;  others  asserted  forthwith 
that  American  oil,  like  everything  else  American,  was  boundless. 
Neither  had  any  grounds  for  their  assertions,  and  therefore  made 
them  with  the  usual  boldness  of  mere  dogmatism. 

Then  came  a  period  of  scare,  started  by  the  fact  that  wells  which 
at  first  spouted  an  inflammable  mixture  of  oil  and  vapor  high  into 
the  air  soon  became  quiescent,  and  from  "  spouting  wells"  became 
"  flowing  wells,"  merely  pouring  out  on  the  surface  a  small  stream  at 
first,  which  gradually  declined  to  a  dribble,  and  finally  ceased  to  flow 
at  all.  Even  those  that  started  modestly  as  flowing  wells  did  the 
latter,  and  thus  appeared  to  become  exhausted. 

This  exhaustion,  however,  was  only  apparent,  as  was  proved  by 
the  application  of  pumps,  which  drew  up  from  wells,  that  had  ceased 
either  to  spout  or  flow,  large  and  apparently  undiminishing  quanti- 
ties of  crude  oil. 

Further  observation  and  thought  revealed  the  cause  of  these 
changes.  It  became  understood  that  the  spouting  was  due  to  the 


274  SCIENCE   IN   SHORT   CHAPTERS. 

tapping  of  a  rock-cavity  containing  oil  of  such  varying  densities  and 
volatility  that  some  of  it  flew  out  as  a  vapor,  or  boiled  at  the  mean 
temperature  of  the  air  of  the  country  or  that  of  the  surrounding 
rocks.  Such  being  the  case,  the  cavity  was  filled  with  high-pressure 
oil-vapor  straining  to  escape.  If  the  bore-hole  tapped  the  crown  or 
highest  curve  of  the  roof  of  such  an  oil  cavern,  it  opened  directly 
into  the  vapor  there  accumulated,  and  the  vapor  itself  rushed  out 
with  such  force  that  a  pillar  of  fire  was  raised  in  the  air  if  a  light 
came  within  some  yards  of  the  orifice.  We  are  told  of  heavy  iron 
boring-rods  that  were  shot  up  to  wondrous  heights — and  we  may  be- 
lieve these  stories  if  we  please. 

If  the  bore-hole  struck  lower  down,  somewhere  on  the  sloping  sides 
or  in  the  shallow  lower  branches  of  the  oil-cavern,  it  dipped  at  once 
into  liquid  oil,  and  this  oil,  being  pressed  by  the  elastic  vapor  of  the 
upper  part,  was  forced  up  as  a  jet  of  spouting  oil. 

In  either  case  these  violent  proceedings  soon  came  to  an  end,  for 
as  the  vapor  or  oil  poured  out,  the  space  above  the  oil-level  where  the 
vapor  had  been  confined  was  increased,  and  its  pressure  diminished, 
till  at  last  it  barely  sufficed  to  raise  the  oil  to  the  surface,  and  after- 
ward failed  to  do  that. 

It  is  quite  clear  from  this  that  the  supplies  are  not ' '  inexhausti- 
ble." The  quantity  of  vapor  having  been  limited,  there  must  also 
be  a  limit  to  the  quantity  of  oil  giving  off  this  vapor  ;  the  space  in 
the  oil- cavern  occupied  by  this  vapor  having  been  limited,  there  must 
be  a  limit  to  the  space  occupied  by  the  oil.  The  quantity  of  oil  may 
be  ten  times,  a  hundred  times,  a  thousand  times,  or  ten  thousand 
times,  greater  than  that  of  the  vapor,  but  in  either  or  any  case  it 
must  come  to  an  end  at  last,  sooner  or  later. 

If  there  were  but  a  few  wells  here  and  there,  as  at  other  similar 
places,  such  as  Rangoon,  the  Persian  oil-wells,  etc.,  the  pumping 
might  continue  for  centuries  and  centuries  ;  but  this  is  not  the  case 
in  America.  The  final  boundaries  of  the  oil-bearing  strata  may  not 
yet  have  been  reached  ;  but  so  far  as  they  are  known  they  are  riddled 
through  and  through,  and  pumped  in  every  direction,  so  that  the 
end  must  come  at  last,  though  with  our  present  knowledge  we  cannot 
say  vihen. 

We  can,  however,  say  how  it  must  come.  It  will  not  be  a  sudden 
stoppage,  but  a  gradual  exhaustion  indicated  by  progressive  diminu- 
tion of  supply.  We  shall  not  be  suddenly  deprived  of  this  important 
source  of  light  and  cheerfulness  ;  but  we  may  at  any  time  begin  to 
feel  the  pinch  of  scarcity  and  consequent  rise  of  price.  This  rise  of 
price  will  check  the  demand,  and  bring  forward  other  supplies  from 
sources  that  now  cannot  be  profitably  worked  on  account  of  the 
cheapness  of  American  petroleum. 

Many  of  the  countries  now  largely  supplied  from  America  have  oil- 
springs  of  their  own,  which  a  rise  of  price  will  speedily  l>ring  into 
paying  operation. 

We  have  nothing  to  fear.  The  fact  that  in  spite  of  the  ruinous 
prices  that  have  recently  prevailed  the  Scotch  oil-makers  continue  to 
exist  at  all,  shows  us  what  they  may  do  with  a  rise  of  even  a  few 
pence  per  gallon.  The  thickness  and  area  of  the  dark  shales  from 
which  their  oil  is  distilled  are  so  great  that  their  exhaustion  is  very 
far  remote  indeed.  The  Americans  have  similar  shales  to  fall  back 
upon  when  the  spontaneous  product  ceases  to  flow,  but  they  are 


AND    "VOLCANIC   BOMBS."       2?5 

quite  incapable  of  competing  with  us  at  home  on  equal  terms— that 
is,  when  both  have  to  obtain  the  oil  as  a  manufactured  product  of 
artificial  distillation. 

If  anything  like  moderation  were  possible  in  America,  the  first  in- 
dications of  scarcity  would  be  followed  by  some  economy  in  work- 
ing ;  but  this  is  not  to  be  anticipated.  It  is  more  likely  that  the  first 
rise  of  prices  will  attract  additional  speculation,  and  the  sinking  of 
more  wells  in  the  hope  of  large  profits,  and  this  of  course  will  shorten 
the  period  of  gradual  exhaustion,  the  commencement  of  which  may, 
for  aught  we  know,  be  very  near  at  hand,  especially  if  the  new  pro- 
jects for  using  petroleum  as  furnace-fuel  under  steam  boilers,  and  for 
the  smelting,  puddling,  and  founding  of  iron  and  other  metals,  are 
carried  out,  as  they  may  be  so  easily  at  present  prices,  and  with  the 
aid  of  pipe-lines  to  carry  the  crude  or  refined  oil  from  the  wells  to 
any  part  of  the  great  American  continent  where  it  may  be  required  in 
large  quantities. 

The  old  story  of  the  goose  that  laid  the  golden  eggs  seems  to  be  in 
course  of  repetition  in  Transatlantic  Petrolia. 

Since  the  above  was  written  I  have  received  from  Dr.  Sterry  Hunt 
a  copy  of  his  interesting  "  Chemical  and  Geological  Essays,"  in  one 
of  which  he  expounds  a  theory  of  the  origin  of  petroleum.  He  states 
that  it  appears  to  him  "  that  the  petroleum,  or  rather  the  materials 
from  which  it  has  been  formed,  existed  in  the  limestone  rocks  from 
the  time  of  their  first  deposition,"  and  "  that  petroleum  and  similar 
bitumens  have  resulted  from  a  peculiar  transformation  of  vegetable 
matters,  or  in  some  cases  of  animal  tissues  analogous  to  these  in 
composition." 

The  objections  on  page  299  apply  to  the  animal  tissues  of  this 
theory,  and  as  regards  the  vegetable  matter  I  think  it  fails  from  the 
want  of  anything  like  an  adequate  supply  in  these  limestone  rocks. 


CHAPTER  XXXIX. 

ON  THE   SO-CALLED    "  CRATER   NECKS"    AND   "VOLCANIC  BOMBS*'    OF 
IRELAND. 

A  Paper  Read  at  the  Geologists'  Association,  December  6th,  1878. 

MR.  HULL,  "  Physical  Geography  and  Geology  of  Ireland,"  p.  68, 
under  the  head  of  "  Volcanic  Necks  and  Basaltic  Dykes,"  says  that 
"  although  the  actual  craters  and  cones  of  eruption  have  been  swept 
from  the  surface  of  the  country  by  the  ruthless  hand  of  time,  yet  the 
old  '  necks,'  by  which  the  volcanic  mouths  were  connected  with  the 
sources  of  eruption  can  occasionally  be  recognized  ;  they  sometimes 
appear  as  masses  of  hard  trap,  columnar  or  otherwise,  projecting  in 
knolls  or  hills  above  the  upper  surface  of  the  sheets  through  which 
they  pierce." 

In  other  cases,  the  "  neck"  consists  of  a  great  pipe  choked  up  by 
bombs  and  blocks  of  trap,  more  or  less  consolidated,  bombs  which 


276  SCIENCE   IN   SHORT   CHAPTERS. 

have  been  shot  into  the  air  and  have  fallen  back  again.  He  then 
refers  to  one  of  these  near  Portrush,  and  proceeds  to  state  that  the 
rock  on  which  stands  the  ruined  Castle  of  Dimluce,  "  is  formed  of 
bombs  of  all  sizes  up  to  six  feet  in  diameter,  of  various  kinds  of 
basalt,  dolerite,  and  amygdaloid  firmly  cemented,  and  presenting  a 
precipitous  face  to  the  sea." 

In  a  note  dated  September,  1877,  Mr.  Hull  states  that  subsequent 
examination,  since  the  above  was  written,  of  the  rock  of  Dunltice 
Castle  and  the  cliffs  adjoining,  has  led  him  "  to  suspect  that  we  have 
here,  instead  of  old  volcanic  necks,  simply  pipes,  formed  by  the 
nitration  out  of  the  chalk  into  which  the  basaltic  masses  have  fallen 
and  slipped  down,  thus  giving  rise  to  their  fragmental  appearance." 

Further  on  (page  146)  he  describes  without  any  sceptical  comment, 
"  the  remarkable  mass  of  agglomerate  made  up  (as  on  the  southern 
flanks  of  Slieve  Gullion)  of  bombs  of  granite,  which  have  been  torn 
up  from  the  granite  mass  of  the  hills  below,  and  blown  through  the 
throat  of  an  old  crater."  Other  geologists  still  adhere  firmly  to  the 
bomb  theory,  some  ascribing  the  bombs  to  subaqueous  rather  than 
subaerial  ejection. 

Immediately  under  Dunluce  Castle  is  a  sea-worn  cavern  or  tunnel 
which  is  about  40  or  50  feet  high  at  its  mouth,  affording  a  fine  sec- 
tion of  this  curious  conglomerate.  The  floor  of  the  cavern  which 
slopes  upward  from  the  sea  is  strewn  with  a  beach  of  boulders.  The 
resemblance  of  this  beach  to  those  I  had  recently  examined  at  the 
foot  of  the  boulder-clay  cliffs  of  Galway  Bay  (and  described  in  a 
paper  read  to  the  British  Association),  suggested  the  explanation  of 
the  origin  of  the  rock  I  am  about  to  offer. 

In  shape  and  size  they  are  exactly  like  the  Galway  shore  boulders, 
those  nearest  the  sea  being  the  most  rounded  ;  higher  up  the  slope, 
where  less  exposed  to  wave  action,  they  are  subangular.  They  differ 
from  the  Galway  boulders  in  being  chiefly  basaltic  instead  of  being 
mainly  composed  of  carboniferous  limestone.  Some  of  these  at  Dun- 
luce  are  granitic,  and  a  few,  if  I  am  not  greatly  mistaken,  are  of  car- 
boniferous limestone.  I  had  not  at  hand  the  means  of  positively  de- 
ciding this. 

Neither  could  I  find  any  unquestionable  examples  of  glacial  stria- 
tion  among  them,  though  at  the  upper  part  I  saw  some  lines  on 
boulders  that  were  very  suggestive  of  partially  obliterated  scratches. 

On  looking  up  at  the  cavern  walls  surrounding  me  the  theory  so 
obviously  suggested  by  the  boulders  on  the  floor  was  strikingly  con- 
firmed by  their  structure  and  general  appearance.  The  imbedded 
"  bombs"  are  subangular,  and  of  irregular  shape  and  varying  compo- 
sition, and  the  matrix  of  the  rock  is  a  brick-like  material  just  such  as 
would  be  formed  by  the  baking  of  boulder  clay  ;  the  inference  that  I 
was  looking  upon  a  bank  or  deposit  of  glacial  drift  that  had  been 
baked  by  volcanic  agency  was  irresistible. 

I  was  unable  to  see  on  any  part  of  the  extensive  section,  or  among 
the  fragments  below,  a  single  specimen  of  an  unequivocal  volcanic 
bomb  ;  no  approach  to  anything  like  those  described  by  Sir  Samuel 
Baker  in  his  "  Nile  Tributaries  of  Abyssinia,"  the  miniature  repre- 
sentatives of  which  ejected  from  the  Bessemer  converterl  have  figured 
and  described  in  Nature,  vol.  3,  pp.  389  and  410,  where  Sir  Samuel 
Baker's  description  is  quoted. 

I  have  witnessed  the  fall  of  masses  of  lava  during  a  minor  eruption 


"CRATER   DECKS''    AND    "  VOLCANIC   BOMBS."      277 

of  an  inner  crater  of  Mount  Vesuvius.  These  as  they  fell  upon  the 
ground  around  me  were  flattened  out  into  thin  cakes.  There  was  no 
approach  to  the  formation  of  subangular  masses,  like  those  displayed 
upon  the  Dunluce  cavern  walls. 

Some  years  ago  a  project  for  melting  the  basaltic  rock  known  as 
"  Kowley  Bag,"  and  casting  it  into  moulds  for  architectural  purposes 
was  carried  out  near  Oldbury,  and  I  had  an  opportunity  of  watching 
the  experiment,  which  was  conducted  on  a  large  scale  at  great  ex- 
pense by  Messrs.  Chance. 

It  was  found  that  if  the  basalt  cooled  rapidly  it  became  a  black 
obsidian,  and  to  prevent  the  formation  of  such  brittle  material,  the 
castings,  and  the  moulds  which  inclosed  them,  had  to  be  kept  at  a 
red  heat  for  some  days,  and  very  gradually  cooled.* 

It  is  physically  impossible  that  lava  ejected  under  water,  in  lumps 
no  larger  than  these  boulders,  could  have  the  granular  structure 
which  they  display. 

The  fundamental  idea  upon  which  this  bomb  theory  is  based  will 
not  bear  examination.  Such  bombs  could  not  have  been  shot  into 
either  air  or  water  and  have  fallen  back  again  into  the  volcanic  neck 
at  any  other  time  than  during  an  actual  eruption  ;  and  at  such  time 
they  could  .not  have  remained  where  they  fell,  and  have  become  im- 
bedded in  any  such  matrix  as  now  contains  them.  True  volcanic 
bombs  and  ordinary  spattering  lumps  of  lava  are,  as  we  know,  fhmg  •* 
obliquely  out  of  active  craters,  and  distributed  around,  while  those 
which  are  ejected  perpendicularly  into  the  air  and  return  are  re- 
ejected,  and  finally  pulverized  into  volcanic  dust  if  this  perpendicular 
ejection  and  return  are  continued  long  enough. 

In  the  course  of  a  rapid  drive  round  the  Antrim  coast  I  observed 
other  examples  of  this  peculiar  conglomerate,  and  have  reason  to  be- 
lieve that  it  is  far  more  common  than  is  generally  supposed.  I  found 
it  remarkably  well  displayed  at  a  place  almost  as  largely  visited  as 
the  Giant's  Causeway,  and  where  it  nevertheless  appears  to  have 
been  hitherto  unnoticed — viz.  Carrick-a-Kede,  where  the  public  car 
stops  to  afford  visitors  an  opportunity  of  examining  or  crossing  the 
rope  bridge,  etc. 

Here  the  whole  formation  is  displayed  in  a  manner  that  strikingly 
illustrates  my  theory. 

There  is  an  overlying  stream  of  basalt  forming  the  surface  of  the 
isolated  rock,  and  this  basalt  rests  directly  upon  a  base  of  conglom- 
erate, having  exactly  the  appearance  that  would  result  from  the  slow 
baking  of  a  mass  of  boulder  clay. 

The  sea  gully  that  separates  the  insular  rock  from  the  mainland 
displays  a  fine  section  above  eighty  feet  in  thickness,  and  has  the 
advantage  of  full  daylight  as  compared  with  Dunluce  Cave.  That  this 
is  no  mere  neck  or  pipe  is  evident  from  its  extent.  Its  position 
below  the  basalt  cap  refutes  the  above  quoted  subsequent  explana- 
tion, which  Mr.  Hull  and  others  have  recently  adopted. 

The  heterogeneous  bomb-like  character  of  the  boulders  is  not  so 
strongly  marked  as  in  the  Dunluce  rock,  and  this  may  arise  from  the 
closer  proximity  of  the  basalt,  which,  coming  here  in  direct  contact, 

*  Geologists  who  may  be  interested  in  seeing  the  results  of  this  experiment, 
will  find  on  the  Edgbaston  Vestry  Hall,  in  Enville  Road,  near  the  Five  Ways. 
Birmingham,  some  columns,  massive  window  pieces,  doorways,  and  ornamental 
steps  cast  from  the  fused  Rowley  Rag  and  slowly  cooled. 


278  SCIENCE   IN   SHORT   CHAPTERS. 

will  be  likely  to  heat  the  clay  matrix  (itself  formed  mainly  of  ice- 
ground  basalt)  to  incipient  fusion,  and  thereby  render  it  more  like 
the  basalt  boulders  it  contains  than  the  other  clay  that  had  been 
less  intensely  heated  on  account  of  greater  distance  from  the  lava- 
flow. 

The  path  leading  to  the  ladder  by  which  the  bridge  is  approached 
passes  over  such  conglomerate,  and  further  extensions  are  seen  in 
sections  around.  I  saw  sufficient  in  the  course  of  my  hurried  visit  to 
indicate  the  existence  of  a  large  area  of  this  particular  formation. 

At  a  short  distance  from  Carrick-a-Rede,  on  the  way  to  Ballycastle, 
the  car  passes  in  sight  of  considerable  deposits  of  ordinary  boulder 
clay  uncovered  and  unaltered. 

The  blocks  of  basalt,  etc.  imbedded  in  this  correspond  in  general 
size  and  shape  with  the  "  bombs,"  excepting  that  some  of  the  latter 
have  a  laminated  or  shaly  character  near  their  surfaces. 

I  regret  my  inability  to  do  justice  to  this  subject  in  consequence  of 
the  fact  that  the  above  explanation  of  the  origin  of  this  curious  for- 
mation only  suggested  itself  when  hurrying  homeward  after  a  some- 
what protracted  visit  to  Ireland.  As  I  may  not  have  an  opportunity 
of  further  investigation  for  some  time  to  come,  I  offer  the  hypothesis 
in  this  crude  form  in  order  that  it  may  be  discussed,  and  either  con- 
firmed or  refuted  by  the  geologists  of  the  Ordnance  Survey,  or  others 
.  who  have  better  opportunities  of  observation  than  I  can  possibly 
command. 

Should  this  conglomerate  prove  to  be,  as  I  suppose,  a  drift  deposit 
altered  by  a  subsequent  flow  of  lava,  it  will  supply  exceedingly  inter- 
esting data  for  the  determination  of  the  chronological  relations  of  the 
glacial  epoch  to  that  period  of  volcanic  activity  to  which  the  lavas  of 
the  N.  E.  of  Ireland  are  due.  Though  it  will  nowise  disturb  the  gen- 
eral conclusion  that  the  great  eruptions  that  overspread  the  creta- 
ceous rocks  of  this  region,  and  supplied  the  boulders  of  my  supposed 
metamorphosed  drift,  occurred  during  the  Miocene  period,  it  will 
show  that  this  volcanic  epoch  was  of  vastly  greater  duration  than  is 
usually  supposed  ;  or  that  there  must  have  been  two  or  more  volcanic 
epochs— pre-glacial,  as  usually  understood,  and  post-glacial,  in  order 
to  supply  the  lava  overflowing  the  drift. 

This  post-glacial  extension  of  the  volcanic  period  has  an  especial 
interest  in  Ireland,  as  the  "  Annals  of  the  Four  Masters,"  and  other 
records  of  ancient  Irish  history  and  tradition,  abound  in  accounts  of 
physical  changes,  many  of  which  correspond  remarkably  with  those 
of  recent  occurrence  in  the  neighborhood  of  active  and  extinct 
volcanoes. 

In  a  paper  read  before  the  Royal  Irish  Academy,  June  23d,  187,3, 
and  published  in  its  "  Proceedings,"  Dr.  Sigerson  has  collected  some  i 
of  the  best  authenticated  of  these  accounts,  and  compares  them  with 
similar  phenomena  recently  observed  in  Naples,  Sicily,  South 
America,  Siberia,  etc.,  etc.  The  "  great  sobriety  of  diction,  and  cir- 
cumstantial precision  of  statement,"  of  names,  dates,  etc.,  which 
characterize  these  accounts  render  them  well  worthy  of  the  sort  of 
comparison  with  strictly  scientific  data  which  Dr.  Sigerson  has  made. 

As  we  now  know  that  man  existed  in  Britain  during  the  inter- 
glacial,  if  not  the  pre-glacial  period,  and  as  so  violent  a  volcanic  dis- 
turbance as  that  which  poured  out  the  lavas  of  Antrim  and  the 
Mourne  district  could  scarcely  have  subsided  suddenly,  but  was 


TRAVERTINE.  279 

probably  followed  by  ages  of  declining  activity,  it  is  not  at  all  sur- 
prising that  this  period  of  minor  activity  should  have  extended  into 
that  of  tradition  and  the  earliest  historical  records. 


CHAPTER  XL. 

TRAVERTINE. 

THE  old  exclamation  about  Augustus  finding  Rome  of  brick  and 
leaving  it  of  marble  deceives  many.  Ancient  Rome  was  by  no  means 
a  marble  city,  although  the  quarries  of  Massa  and  Carrara  are  not  far 
distant.  The  staple  building  materials  of  the  Imperial  City,  even  in 
its  palmiest  days,  were  brick  and  travertine.  The  brick,  however, 
was  verjr  different  from  the  porous  cakes  of  crudely  burned  clay  of 
which  the  modern  metropolis  of  the  world  is  built.  I  have  examined 
on  the  spot  a  great  many  specimens,  and  found  them  all  to  be  of 
remarkably  compact  structure,  somewhere  between  the  material  of 
modern  terra-cotta  and  that  of  common  flower-pots,  and  similarly  in- 
termediate in  color.  The  Roman  builders  appear  to  have  had  no 
standard  size,  the  bricks  vary  even  in  the  same  building — the  Coli- 
seum for  example  ;  all  that  I  have  seen  are  much  thinner  than  our 
bricks — we  should  call  them  tiles. 

But  the  most  characteristic  material  is  the  travertine.  The  walls 
of  the  Coliseum  are  made  up  of  a  mixture  of  this  and  the  tiles  above 
mentioned.  The  same  is  the  case  with  most  of  the  other  very  mass- 
ive ruins,  as  the  baths,  etc.  Many  of  the  temples  with  columns  and 
facing  of  marble  have  inner  walls  built  of  this  mixture,  while  others 
are  entirely  of  travertine. 

I  was  greatly  surprised  at  the  wondrous  imperishability  of  this 
remarkable  material.  In  buildings  of  which  the  smooth  crystalline 
marble  had  lost  all  its  sharpness  and  original  surface,  this  dirty,  yel- 
low, spongy-looking  limestone  remained  without  the  slightest  indica- 
tion of  weathering.  A  most  remarkable  instance  of  this  is  afforded 
by  the  temple  of  Neptune,  at  Paesturn,  in  Calabria.  This  is  the  most 
perfect  rain  of  a  pure  classic  temple  that  now  remains  in  existence, 
and  in  my  opinion  is  the  finest.  I  prefer  it  even  to  the  Parthenon. 

We  have  a  little  sample  of  it  is  London.  The  Doric  columns  at  the 
entrance  of  the  Euston  station  are  copies  of  those  of  its  peristyle. 
The  originals  are  of  travertine,  the  blocks  forming  them  are  laid  upon 
each  other  without  mortar  or  cement,  and  so  truly  flattened  that  in 
walking  round  the  building  and  carefully  prying,  I  could  find  no 
crevice  into  which  a  slip  of  ordinary  writing  paper  or  the  blade  of  a 
pen-knife  could  be  inserted.  Yet  this  temple  was  an  antiquarian 
monument  in  the  days  of  the  Roman  emperors. 

The  rough  natural  surface  of  the  stone  is  exposed,  and  at  first  sight 
appears  as  though  weathered,  but  this  appearance  is  simply  due  to 
its  natural  sponge-like  structure.  It  appears  to  have  been  coated 
with  some  sort  of  stucco  or  smoothing  film,  which  either  by  forming 
a  thin  layer,  or  possibly  by  only  filling  up  the  pores  of  the  travertine, 
gave  a  smooth  surface  upon  which  the  coloring  was  applied.  This  is 


280  SCIENCE   IN   SHORT   CHAPTEES. 

now  only  indistinctly  visible  here  and  there,  and  if  I  remember 
rightly,  some  have  disputed  its  existence. 

But  this  travertine,  though  so  familiar  to  the  Italian,  is  such  a 
rarity  here  that  some  further  description  of  its  structure  and  compo- 
sition may  be  demanded.  It  is  a  limestone  formed  by  chemical  pre- 
cipitation. Most  limestones  are  more  or  less  of  organic  origin,  are 
agglomerations  of  shells,  corals,  etc.,  but  this  is  formed  by  the  same 
kind  of  action  as  that  which  produces  the  stalactites  in  limestone 
caverns.  It  has  some  resemblance  to  the  incrustation  formed  on 
boilers  by  calcareous  water.  Although  the  material  of  so  many 
ancient  edifices,  it  is,  geologically  speaking,  the  youngest  of  all  the 
hard  rocks.  Its  formation  is  now  in  progress  at  some  of  the  very 
quarries  that  supplied  Imperial  Borne. 

On  the  Campagna,  between  Eonie  and  Tivoli,  is  a  small  circular 
lake,  from  which  a  stream  of  tepid  water,  that  wells  up  from  below, 
is  continually  flowing.  Its  local  name  is  "  The  Lake  of  Tartarus." 
The  water,  like  that  of  Zoedone,  or  soda-water  or  champagne,  is 
supersaturated  with  carbonic  acid  that  was  forced  into  it  while  under 
pressure  down  below.  This  carbonic  acid  has  dissolved  some  of  the 
limestones  through  which  the  subterranean  water  passes,  and  when 
it  comes  to  the  surface,  the  carbonic  acid  flies  away  like  that  which 
escapes  when  we  uncork  a  bottle  of  soda-water,  though  less  suddenly, 
and  the  lime  losing  its  solvent  is  precipitated,  and  forms  a  crust  on 
whatever  is  covered  by  the  water. 

When  I  visited  this  lake  in  the  month  of  February  it  was  sur- 
rounded by  a  chevaux  de  frise  of  an  extraordinary  character  ;  thou- 
sands of  tubes  of  about  half  an  inch  to  one  inch  in  diameter  outside, 
with  calcareous  walls  about  one  eighth  of  an  inch  in  thickness.  These 
were  standing  up  from  two  to  three  feet  high,  and  so  close  together 
that  we  had  to  break  our  way  through  the  dense  palisade  they  formed 
in  order  to  reach  the  margin  of  the  lake.  After  some  consideration 
and  inquiry,  their  origin  was  discovered.  They  are  the  incrusted 
remains  of  bullrushes  that  had  flourished  in  the  summer  and  died 
down  since.  During  the  time  of  their  growth  the  water  had  risen, 
and  thus  they  became  coated  with  a  crust  of  compact  travertine. 
This  deposition  takes  place  so  rapidly  that  a  piece  of  lace  left  in  the 
rake  for  a  few  hours  comes  out  quite  stiff,  every  thread  being  coated 
with  limestone.  Such  specimens,  and  twigs  similarly  covered,  are 
wold  to  tourists  or  prepared  by  them  if  they  have  time  to  stop.  Sir 
Humphry  Davy  drove  a  stick  into  the  bottom  of  the  lake  and  left  it 
standing  upright  in  the  water  from  May  to  the  following  April,  and 
then  had  some  difficulty  in  breaking  with  a  sharp-pointed  hammer 
the  crust  formed  round  the  stick.  This  crust  was  several  inches  in 
thickness.  That  which  I  saw  round  the  ex-bulrushes  may  have  all 
been  formed  in  a  few  days  or  weeks.  The  rivulet  that  flows  from  the 
lake  deposits  travertine  throughout  its  course,  and  when  it  overflows 
leaves  every  blade  of  grass  that  it  covers  incrusted  with  this  limestone. 

Near  to  the  Lake  of  Tartarus  is  the  tiolfatara  lake  which  contains 
similar  calcareous  water,  but  strongly  impregnated  with  sulphuretted 
hydrogen  ;  it  consequently  deposits  a  mixture  of  carbonate  and  sul- 
phide of  calcium,  a  sort  of  porous  tufa,  some  of  it  so  porous  that  it 
floats  like  a  stony  scum,  forming  what  the  cicerone  call  "  floating 
islands."  Lyell,  in  his  "Principles  of  Geology,"  confounds  these 
lakes,  and  describes  Tartarus  under  the  name  of  Solfatara. 


THE   CORROSION    OF   BUILDING   STOXES.  281 

The  travertine  used  as  a  building  stone  is  chiefly  derived  from  the 
quarries  of  Ponte  Lucano,  and  is  the  deposit  that  was  formed  on  the 
bed  of  a  lake  like  that  of  Tartarus.  The  celebrated  cascade  of  the 
Anio  at  Tivoli  forms  calcareous  stalactites,  and  all  the  country  round 
has  rivulets,  caverns,  and  deposits  where  this  formation  may  be  seen 
in  progress  or  completed. 

It  varies  considerably  in  structure :  some  specimens  are  compact 
and  smooth,  others  have  the  appearance  of  a  petrified  moss,  and  great 
varieties  may  be  found  among  the  materials  of  a  single  building.  It 
is,  however,  usually  rough  and  more  or  less  spongy-looking,  as  above 
stated,  but  this  structure  does  not  seem  to  affect  its  stability,  at  least, 
not  in  the  climate  of  Italy.  Whether  it  would  stand  long  frosts  is  an 
open  question.  The  night  frosts  at  and  about  Home  are  rather 
severe,  but  usually  followed  by  a  warm  sunny  day  ;  thus  there  is  no 
great  penetration  of  ice. 

Every  specimen  I  have  examined  shows  a  remarkable  compactness 
of  molecular  structure  in  spite  of  visible  porosity.  All  give  out  a  clear 
metallic  ring  when  struck,  and  the  intimate  surface,  if  I  may  so  de- 
scribe the  surface  of  the  worm-like  structure  it  sometimes  displays, 
is  always  clear  and  smooth  as  though  varnished.  To  this  I  attribute 
its  durability.  Lest  the  above  description  should  appear  self-contra- 
dictory, I  will  explain  a  little  further.  If  melted  glass  were  run  into 
threads,  and  those  threads  while  soft  were  allowed  to  agglomerate 
loosely  into  a  convoluted  mass,  it  would,  as  regarded  in  mass,  have  a 
porous  or  spongy-looking  structure,  but  nevertheless  its  molecular 
structure  would  be  compact  and  vitreous  ;  there  would  be  mechani- 
cal, but  not  molecular,  porosity.  Travertine  is  similar. 

Have  we  any  travertine  in  England  ?  This  is  a  practical  question 
of  some  importance,  and  one  to  which  I  have  no  hesitation  in  reply- 
ing, Yes.  There  is  plenty  formed  and  forming  in  the  neighborhood 
of  Matlock,  but  that  which  I  have  seen  on  the  face  of  caverns,  etc.  is 
not  so  compact  and  metal-like  as  the  Italian.  This,  however,  does 
not  prove  the  entire  absence  of  the  useful  travertine.  Not  having 
any  commercial  interest  in  the  search,  I  have  only  looked  at  what  has 
come  in  my  way,  but  have  little  doubt  that  there  are  other  kinds  be- 
sides those  I  saw.  I  have  also  seen  travertine  in  course  of  formation 
in  Ireland,  where  I  think  there  is  a  fine  field  for  exploration  in  the 
mountain  limestone  regions,  which  have  been  disturbed  by  volcanic 
action  of  the  Miocene  period.  The  travertines  of  Italy  are  found  in 
the  neighborhood  of  extinct  volcanoes. 

The  classic  associations  of  this  material,  its  remarkable  stability, 
and  the  facility  with  which  it  may  be  worked,  render  it  worthy  of 
more  attention  than  it  has  yet  received  from  British  builders. 


CHAPTEE  XLI. 

THE    CORKOSION    OF   BUTLDING   STONES. 

ABOUT  fifty  years  ago  two  eminent  French  chemists  visited  London, 
and  rather  "astonished  the  natives"  by  a  curious  feature  of  their 
dress.  They  wore  on  their  hats  large  patches  of  colored  paper. 


282  SCIENCE   IN   SHORT   CHAPTERS. 

Coining  as  they  did  from  Paris,  many  supposed  that  this  was  one  of 
the  latest  Paris  fashions,  and  the  dandies  of  the  period  narrowly 
escaped  the  compulsion  to  follow  it.  They  probably  would  have 
done  so  had  the  Frenchmen  shown  any  attempt  at  decorative  shaping 
of  the  paper.  They  neglected  this  because  it  was  litnrus  paper,  and 
their  object  in  attaching  it  to  their  hats  was  to  test  the  impurities  of 
the  London  atmosphere. 

Blue  litmus  paper,  as  everybody  knows  nowadays,  turns  red  when 
exposed  to  an  acid.  The  French  chemists  found  that  their  hat-deco- 
rations changed  color,  and  indicated  the  presence  of  acid  in  the  air 
of  London  ;  but  when  they  left  the  metropolis  and  wandered  in  the 
open  fields  their  blue  litmus  paper  retained  its  original  color.  By 
using  alkaline  paper  they  contrived  to  collect  enough  of  the  acid  to 
test  its  composition.  They  found  it  to  be  the  acid  which  is  formed 
by  the  burning  of  sulphur,  and  attributed  its  existence  to  the  sulphur 
of  our  coal.  At  this  time  the  domestic  use  of  coal  was  scarcely 
known  in  Paris. 

Subsequent  experiments  have  proved  that  they  were  right  ;  that 
the  air  of  London  contains  a  very  practical  quantity  of  sulphurous 
and  sulphuric  acids,  which  are  due  to  the  combustion  of  that  yellow 
shining  material  more  or  less  visible  in  most  kinds  of  coal,  and  has 
been  occasionally  supposed  to  be  gold.  It  is  iron  pyrites,  a  com- 
pound of  iron  and  sulphur.  When  heated  the  sulphur  is  separated 
aad  burns,  producing  sulphurous  acid,  which  exposed  to  moist  air 
gradually  takes  up  more  oxygen  and  becomes  sulphuric  acid,  which 
in  concentrated  solution  is  oil  of  vitriol.  In  the  air  it  is  very  much 
diluted  by  diffusion,  but  is  still  strong  enough  to  do  mischief  to  some 
kinds  of  building  materials. 

In  manufacturing  towns,  such  as  Birmingham  and  Sheffield,  the 
quantity  of  this  acid  in  the  air  is  much  greater  than  in  London,  and 
there  its  mischief  is  consequently  more  distinctly  visible.  The 
church  of  St.  Philip,  which  stands  nearly  in  the  middle  of  Birming- 
ham, and  is  surrounded  by  an  old  churchyard,  was  so  corroded  by 
this  acid  that  the  stone  peeled  away  on  all  sides,  and  its  condition 
was  most  deplorable.  The  tombstones  were  similarly  disintegrated 
on  their  surfaces,  and  inscriptions  quite  obliterated.  It  became  so 
bad  that  a  few  years  ago  restoration  was  necessary,  and  it  was  newly 
faced  accordingly. 

Some  of  the  old  tombstones  that  are  preserved  may  still  be  seen 
against  the  church  wall,  and  their  peculiar  structure  is  well  worthy 
of  study.  They  display  a  lamination  or  peeling  away  due  to  unequal 
corrosion,  certain  layers  of  the  material  of  the  stone  having  been  evi- 
dently eaten  away  more  rapidly  than  others.  Anybody  visiting  Bir- 
mingham may  easily  examine  these,  as  St.  Philip's  churchyard  is 
situated  between  the  two  railway  stations  of  New  Street  and  Snow 
Hill,  and  is  but  two  minutes'  walk  from  either. 

Other  stone  buildings  in  the  town  have  suffered,  but  in  very  differ- 
ent degrees,  and  some  have  quite  escaped,  proving  the  necessity  of 
careful  selection  of  material  wherever  coal  fires  abound.  In  Birming- 
ham the  action  of  coal  fires  is  assisted  by  other  sources  of  acid  vapor. 
The  process  of  "  pickling"  brass  castings — i.e.,  brightening  their  sur- 
face by  dipping  first  in  common  nitric  acid  ("  pickle  acky")  and  then 
in  water,  is  attended  with  considerable  evolution  of  acid  fumes.  Be- 
eides  this  very  widespread  use  of  acid,  there  are  several  chemical 


THE    CORROSION    OF    BUILDING    STOXE3.  283 

manufactories  that  throw  still  more  acid  into  the  air  immediately 
surrounding  them. 

As  an  example  of  the  action  of  the  atmospheric  acids  of  London 
upon  building  stones,  I  have  but  to  name  the  Houses  of  Parliament, 
which  have  only  been  rescued  from  superficial  ruin  by  the  patchwork 
replacing  of  certain  blocks  of  stone,  and  various  devices  of  silicious 
and  other  washings  that  have  been  carried  out  at  great  cost  to  the 
nation.  That  such  an  unsuitable  material  should  have  been  used  is 
disgraceful  to  all  concerned.  The  ruin  commenced  before  the  build- 
ing was  finished.  At  the  time  when  its  erection  commenced  there 
were  abundant  evidences  of  the  ruinous  action  of  London  atmosphere 
on  some  kinds  of  stone  and  the  capability  of  others  to  resist  it,  for 
while  many  modern  buildings  are  peeling  and  crumbling,  some  of  the 
oldest  in  the  midst  of  the  city  show  scarcely  any  signs  of  corrosion. 

The  Birmingham  and  Midland  Institute  was  established  and  in 
practical  operation  a  few  years  before  the  present  noble  building  was 
erected.  I  was  the  first  teacher  there  and  conducted  the  Science 
classes  in  the  temporary  premises  in  Cannon  Street.  Having  ob- 
served with  some  interest  the  disintegration  of  St.  Philip's  Church 
and  other  buildings,  I  was  anxious  for  the  safety  of  the  new  Institute 
buildings,  and  accordingly  made  some  experiments  upon  the  material 
proposed  to  be  used  by  the  architect.  My  method  of  testing  was 
very  simple,  and  as  the  practical  result  has  verified  my  anticipations 
I  think  it  might  be  adopted  by  others. 

First,  I  immersed  some  lumps  of  the  stone  in  moderately  strong 
solutions  of  sulphuric  and  hydrochloric  acids  successively,  and  ob- 
served whether  any  visible  action  occurred  after  some  days.  There 
was  none.  I  then  roughly  tested  the  crushing  pressure  of  small  sam- 
ples in  their  natural  state,  and  subjected  similar  sized  pieces  to  the 
same  test  after  they  had  been  immersed  in  the  acids.  I  found  thus 
that  there  were  no  evidences  of  internal  disintegration  even  after 
several  days'  immersion,  and  therefore  inferred  that  the  stone  would 
stand  the  acid  vapors  of  the  Birmingham  atmosphere.  This  has  been 
the  case  with  that  portion  of  the  building  that  was  built  of  the  mate- 
rial I  tested.  As  I  know  nothing  of  the  stone  which  is  used  for  the 
extension  of  the  building  under  the  present  architect,  Mr.  Chamber- 
lain, I  am  unable  to  make  any  forecast  of  its  probable  durability. 

The  experiments  I  made  at  the  time  named  with  this  and  other 
building  materials  justified  the  conclusion  that  the  worst  of  all  mate- 
rial for  exposure  to  acid  atmospheres  is  a  sandstone,  the  particles  of 
which  are  held  together  by  limestone,  or  are  otherwise  surrounded 
by  or  intermingled  with  limestone  ;  and  that  the  best  of  ordinary 
material  is  a  pure  sandstone  quite  free  from  lime.  I  do  not  here 
consider  such  luxurious  material  as  granites  or  porphyries. 

Compact  limestone,  such  as  good  homogeneous  marble,  stands 
fairly  well,  although  it  is  slowly  corroded.  The  corrosion,  however, 
in  this  case,  is  purely  superficial  and  tolerably  uniform.  It  is  a  very 
slow  washing  away  of  the  surface,  without  any  disintegration  such  as 
occurs  where  a  small  quantity  of  limestone  acts  as  binding  material 
to  hold  together  a  large  quantity  of  silicious  or  sandy  material,  and 
where  the  agglomeration  is  porous,  and  the  stone  is  so  laid  that  a 
downward  infiltration  of  water  can  take  place  ;  for  it  must  be  remem- 
bered that  although  the  acid  originally  exists  as  vapor  in  the  air,  it  is 
taken  up  by  the  falling  rain,  and  the  mischief  is  directly  done  to  the 


SCIENCE   IN   SHORT   CHAPTERS. 

stone  by  this  acidified  water.  This,  of  course,  is  very  weak  acid  in- 
deed. That  which  I  used  for  testing  the  stone  was  many  thousand 
times  stronger,  but  then  I  exposed  the  stone  for  only  a  few  days  in- 
stead  of  many  thousand  days. 

As  above  stated,  my  experiments  were  but  rude,  but  I  think  it 
would  be  quite  worth  while  to  construct  crushing  apparatus  capable 
of  registering  accurately  the  pressure  used,  and  to  operate  with  stand- 
ard solutions  of  acid  upon  carefully  squared  blocks  of  standard  size, 
and  thus  to  make  comparative  tests  of  various  samples  of  stone  when 
competitions  for  building  materials  are  offered.  In  the  case  of  the 
Birmingham  and  Midland  Institute  building  there  was  no  such  com- 

Eetition  ;  the  choice  was  left  entirely  to  the  architect,  and  my  exaui- 
lation  was  unofficially  conducted  upon  the  material  already  chosen 
with  the  intent  of  protesting  if  it  failed.     As  it  stood  the  test  I 
merely  reported  the  results  informally  to  the  architect,  the  late  Sir 
Edward  Barry,  no  further  action  being  demanded. 


CHAPTEE  XLII. 

HOME   GAKDENS   FOE   SMOKY   TOWNS. 

THE  poetical  philanthropists  of  the  shepherd  and  shepherdess 
school,  if  any  still  remain,  may  find  abundant  material  for  their  dole- 
ful denunciations  of  modern  civilization  on  journeying  among  the 
house-tops  by  any  of  our  over-ground  metropolitan  and  suburban 
railways,  and  contemplating  therefrom  the  panorama  presented  by  a 
rapid  succession  of  London  back-yards.  The  sandy  Sahara  and  the 
saline  deserts  of  Central  Asia  are  bright  and  breezy,  rural  and  cheer- 
ful, compared  with  these  foul,  soot- smeared,  lumber-strewn  areas  of 
desolation. 

The  object  of  this  paper  is  to  propose  a  remedy  for  these  metropol- 
itan measle-spots,  by  converting  them  into  gardens  that  shall  afford 
both  pleasure  and  profit  to  all  concerned. 

A  very  obvious  mode  of  doing  this  would  be  to  cover  them  with 
glass,  and  thus  convert  them  into  winter  gardens  or  conservatories. 
The  cost  of  this  at  once  places  it  beyond  practical  reach  ;  but  even  if 
the  cost  were  disregarded,  as  it  might  be  in  some  instances,  such 
covering  in  would  not  be  permissible  on  sanitary  grounds  ;  for,  dole- 
I  ful  and  dreary  as  they  are,  the  back-yards  of  London  perform  one 
^ry  important  and  necessary  function  ;  they  act  as  ventilation-shafts 
between  the  house-backs  of  the  more  densely  populated  neighborhoods. 

At  one  time  I  thought  of  proposing  the  establishment  of  horticult- 
ural home-missions  for  promoting  the  dissemination  of  flower-pot 
shrubs  in  the  metropolis,  and  of  showing  how  much  the  atmosphere 
of  London  would  be  improved  if  every  London  family  had  one  little 
sweetbrier.bush,  a  lavender  plant,  or  a  hardy  heliotrope  to  each  of  its 
members  ;  so  that  a  couple  of  million  of  such  ozone  generators  should 
breathe  their  sweetness  into  the  dank  and  dead  atmosphere  of  the 
denser  central  regions  of  London. 

A  little  practical  experience  of  the  difficulty  of  growing  a  clean  cab- 
bage, or  maintaining  alive  any  sort  of  shrub  in  the  midst  of  our  soot- 


HOJIE   GARDENS   FOR   SMOKY   TOWNS.  285 

drizzle,  satisfied  me  that  the  mission  would  fail,  even  though  the 
sweetbriers  were  given  away  by  the  district  visitors  ;  for  these  simple 
hardy  plants  perish  in  a  mid-London  atmosphere  unless  their  leaves 
are  periodically  sponged  and  syringed,  to  wash  away  the  soot  parti- 
cles that  otherwise  close  their  stomata  and  suffocate  the  plant. 

It  is  this  deposit  that  stunts  or  destroys  all  our  London  vegetation, 
with  the  exception  of  those  trees  which,  like  the  planes,  have  a  de- 
ciduous bark  and  cuticle. 

Some  simple  and  inexpensive  means  of  protecting  vegetation  from 
London  soot  are,  therefore,  most  desirable. 

When  the  Midland  Institute  commenced  its  existence  in  temporary 
buildings  in  Cannon  Street,  Birmingham,  in  3854,  I  was  compelled  to 
ventilate  my  class-rooms  by  temporary  devices,  one  of  which  was  to 
throw  open  the  existing  windows,  and  protect  the  students  from  the 
heavy  blast  of  entering  air  by  straining  it  through  a  strong  gauze-like 
fabric  stretched  over  the  opening. 

After  a  short  time  the  tammy  became  useless  for  its  intended  pur- 
pose ;  its  interstices  were  choked  with  a  deposit  of  carbon.  On  ex- 
amining this,  I  found  that  the  black  deposit  was  all  on  the  outside, 
showing  that  a  nitration  of  the  air  had  occurred.  Even  when  the 
tammy  was  replaced  by  perforated  zinc,  puttied  into  the  window 
frames  in  the  place  of  glass  panes,  it  was  found  necessary  to  fre- 
quently wash  the  zinc,  in  order  to  keep  the  perforations  open. 

The  recollection  of  this  experience  suggested  that  if  a  gauze-like 
fabric  cheaper  and  stronger  than  the  tammy  can  be  obtained,  and  a 
sort  of  greenhouse  made  with  this  in  the  place  of  glass,  the  problem 
of  converting  London  back-yards  into  gardens  might  be  solved. 

After  some  inquiries  and  failures  in  the  trial  of  various  cheap  fab- 
rics, I  found  one  that  is  already  to  be  had,  and  well  adapted  to  the 
purpose.  It  is  called  "  wall  canvas,"  or  "  scrim,"  is  retailed  at  3|c7. 

Eer  yard,  and  is  one  yard  wide.  If  I  am  rightly  informed,  it  may  be 
ought  in  wholesale  quantities  at  about  2£d.  per  square  yard — i.e.,  one 
farthing  per  square  foot.  This  fabric  is  made  of  coarse  unbleached 
thread  yarn,  very  strong  and  open  in  structure.  The  light  passes  so 
freely  through  it,  that  when  hung  before  a  window  the  loss  of  light  in 
the  room  is  barely  perceptible.  When  a  piece  is  stretched  upon  a 
frame,  a  printed  placard,  or  even  a  newspaper,  may  be  read  through  it. 
The  yarn  being  loosely  spun,  fine  flutfy  filaments  stand  out  and  bar 
the  interstices  against  the  passage  of  even  very  minute  carbonaceous 
particles.  These  filaments  may  be  seen  by  holding  it  up  to  the  light. 
The  fabric  being  one  yard  wide,  and  of  any  length  required,  all 
that  is  needed  for  a  roof  or  side  walls  is  a  skeleton  made  of  lines  or 
runs  of  quartering,  at  3  feet  distance  from  each  other.  The  cost  of 
such  quartering,  made  of  pitch  pine,  the  best  material  for  outside 
work,  is  under  one  penny  per  foot  run  ;  of  common  white  deal,  about 
three  farthings.  Thus  the  cost  of  material  for  a  roof,  say  a  lean-to 
from  a  wall-top  to  the  side  of  a  house,  which  would  be  the  most  com- 
monly demanded  form,  of  30  feet  by  10  feet,  i.e.,  300  square  feet, 
would  be— 

s.     cl. 
110  feet  of  quartering  (11  lengths)  at  Id.        .    '  .       .         .        92 

300  square  feet  of  canvas,  at  irf .6 

Nails  and  tacks,  say .10 

*  See  foot-note,  page  293.  10     5 


286  SCIENCE   HT   SHORT   CHAPTERS. 

The  size  of  the  quartering  proposed  is  2|  by  1£  inch,  which,  laid 
edgewise,  would  bear  the  weight  of  a  man  on  a  plank  while  nail  ing 
down  the  canvas.  The  canvas  has  a  stout  cord-like  edge  or  selvage 
that  holds  the  nails  well. 

I  find  that  what  are  called  "  French  tacks"'  are  well  suited  for  nail- 
ing it  down.  They  are  made  of  wire  well  pointed,  have  good-sized 
Hat  clout  heads,  and  are  very  cheap.  They  are  incomparably  superior 
to  the  ordinary  rubbish  sold  as  "  tin  tacks"  or  "  cut  tacks."  The 
construction  of  such  a  conservatory  is  so  simple  that  any  industrious 
artisan  or  clerk  with  any  mechanical  ingenuity  could,  with  the  aid 
of  a  boy,  do  it  all  himself.  No  special  skill  is  required  for  any  part 
of  the  work,  and  no  other  tools  than  a  rule,  a  saw,  and  a  hammer. 
>Side  posts  and  stronger  end  rails  would  in  seme  cases  be  demanded. 

I  have  not  been  able  to  fairly  carry  out  this  project,  inasmuch  as  I 
reside  at  Twickenham,  beyond  the  reach  of  the  black  showers  of 
London  soot.  I  have,  however,  made  some  investigations  relative  to 
the  climate  which  results  from  such  inclosure. 

This  was  done  by  covering  a  small  skeleton  frame  with  the  canvas, 
putting  it  upon  the  ground  over  some  cabbage  plants,  etc.,  and  plac- 
ing registering  thermometers  on  the  ground  inside,  and  in  similar 
position  outside  the  frame  ;  also  by  removing  the  glass  cover  of  a 
cucumber  frame,  and  replacing  it  by  a  frame  on  which  the  canvas  is 
stretched. 

I  planted  300  cabbages  in  November  last,  in  rows  on  the  open 
ground,  and  placed  the  canvas-covered  frame  over  18  of  them.  At 
the  present  date,  March  loth,  only  26  of  the  282  outside  plants  are 
visible  above  ground.  All  the  rest  have  been  cut  off  by  the  severe 
frost.  Under  the  frame  all  are  flourishing. 

I  find  that  the  difference  between  the  maximum  and  the  minimum 
temperatures  varies  with  the  condition  of  the  sky.  In  cloudy 
weather,  the  difference  between  the  inside  and  the  outside  rarely 
exceeds  2°  Fahr.,  and  occasionally  there  is  no  difference.  In  clear 
weather  the  difference  is  considerable.  During  the  day  the  outside 
thermometer  registers  from  four  or  five  to  seven  or  eight  degrees 
above  that  within  the  screen  during  the  sunshine.  At  night  the 
minimum  thermometers  show  a  difference  which  in  one  case  reached 
143 — i.e.,  between  23d  and  24th  February,  when  the  lowest  tempera- 
ture I  have  observed  was  reached.  The  outside  thermometer  then 
fell  to  8°  Fahr.,  the  inside  to  22°.  On  the  night  of  the  24th  and  25th 
they  registered  15^°  oiitside,  25^°  inside.  On  other,  or  ordinary 
clear  frosty  nights,  with  E.  and  N.  and  N.  E.  winds,  the  difference 
has  ranged  between  4°  and  6°,  usually  within  a  fraction  of  the  aver- 
age, 5°. 

The  uniformity  of  this  during  the  recent  bright  frosty  nights,  fol- 
lowed by  warm  sunny  days,  has  been  very  remarkable,  so  much  so 
that  I  think  I  may  venture  to  state  that  5°  may  be  expected  as  the 
general  protecting  effect  of  a  covering  of  such  canvas  from  the  mis- 
chievous action  of  our  spring  frosts  which  are  due  to  nocturnal  radia- 
tion into  free  space.  Thus  we  obtain  a  climate,  the  mean  of  which 
would  be  about  the  same  as  outside,  but  subject  to  far  less  variation. 
How  will  this  affect  the  growth  of  plants  desirable  to  cultivate  in  the 
proposed  canvas  conservatories  ? 

In  the  first  place,  we  must  not  expect  the  results  obtainable  under 
glass,  which  by  freely  transmitting  the  bright  solar  rays,  and  absorb- 


HOME   GARDENS   FOR   SMOKY  TOWN'S.  287 

ing  or  resisting  the  passage  of  the  obscure  rays  from  the  heated  soil, 
produces,  during  sunshine,  a  tropical  climate  here  in  our  latitudes. 
We  may  therefore  at  ones  set  aside  any  expectation  of  rearing  exotic 
plants  of  any  kind  ;  even  our  native  and  acclimatized  plants,  which  re- 
quire the  maximum  heat  of  English  sunshine,  are  not  likely  to  flourish. 

On  the  other  hand,  all  those  which  demand  moderate  protection 
from  sudden  frosts,  especially  from  spring  frosts,  and  which  flourish 
when  we  have  a  long  mild  spring  and  summer,  are  likely  to  be  reared 
with  especial  success. 

This  includes  nearly  all  our  table  vegetables,  our  salads,  kitchen 
herbs,  and  British  fruits,  all  our  British  and  many  exotic  ferns,  and, 
I  believe,  most  of  our  out-of-door  plants,  both  wild  and  cultivated. 

As  the  subject  of  ornamental  flowers  is  a  very  large  one,  and  one 
with  the  cultivation  of  which  I  have  very  little  practical  acquaint- 
ance, I  will  pass  it  over  ;  but  must  simply  indicate  that,  in  respect  to 
ferns,  the  canvas  inclosure  offers  a  combination  of  most  desirable 
conditions.  The  slight  shade,  the  comparatively  uniform  tempera- 
ture, and  the  moderated  exhalation  are  just  those  of  a  luxuriant  fern 
dingle. 

Respecting  the  useful  or  economic  products  I  can  speak  with  more 
confidence,  that  being  my  special  department  in  our  family  or  home 
gardening,  which,  as  physical  discipline,  I  have  always  conducted 
myself,  with  a  minimum  of  professional  aid. 

My  experience  of  a  small  garden  leads  me  to  give  first  place  to 
salads.  A  yard  square  of  rich  soil,  well  managed,  will  yield  a  hand- 
some and  delicious  weekly  dish  of  salad  nearly  all  the  year  round  ; 
and,  at  the  same  rate,  seven  or  eight  square  yards  will  supply  a  daily 
dish — including  lettuces,  endives,  radishes,  spring  onions,  mustard, 
and  various  kinds  of  cress,  and  fancy  salads,  ail  in  a  state  of  fresh- 
ness otherwise  unattainable  by  the  Londoner.  My  only  difficulty  has 
arisen  from  irregularity  of  supply.  From  the  small  area  allowed  for 
salads,  I  have  been  over-supplied  in  July,  August  and  September, 
and  reduced  to  in-door  or  frame-grown  mustard  and  cress  during  the 
winter.  With  the  equable  insular  climate  obtainable  under  the  can- 
vas, this  difficulty  will  be  greatly  diminished  ;  and  besides  this,  most 
of  the  salads  are  improved  by  partial  shade,  lettuces  and  endives 
more  blanched  and  delicate  than  when  exposed  to  scorching  sun, 
radishes  less  fibrous,  mustard,  cress,  etc.  milder  in  flavor  and  more 
succulent. 

The  multitude  of  savory  kitchen  herbs  that  are  so  sadly  neglected 
in  English  cookery  (especially  in  the  food  of  the  town  artisan  and 
clerk),  all,  with  scarcely  an  exception,  demand  an  equable  climate 
and  protection  from  our  destructive  spring  frosts.  These  occupy 
very  little  space,  less  even  than  salads,  and  are  wanted  in  such  small 
quantities  at  a  time,  and  so  frequently,  that  the  hard-worked  house- 
wife commonly  neglects  them  altogether,  rather  than  fetch  them  from 
the  green-grocer's  in  their  exorbitantly  small  pennyworths.  If  she 
could  step  into  the  back  yard,  and  gather  her  parsley,  sage,  thyme, 
winter  savory,  mint,  marjoram,  bay  leaf,  rosemary,  etc.,  the  dinner 
would  become  far  more  savory,*  and  the  demand  for  the  alcoholic 
substitutes  for  relishing  food  proportionably  diminished. 

My  strongest  anticipations,  however,  lie  in  the  direction  of  com- 
mon fruits — apples,  pears,  cherries,  plums  of  all  kinds,  peaches, 
nectarines,  gooseberries,  currants,  raspberries,  strawberries,  etc. 


288  SCIENCE   IX   SHORf   CHAPTERS. 

The  most  luxuriant  growth  of  cherries,  currants,  gooseberries,  and 
raspberries  I  have  ever  seen  in  any  part  of  the  world  that  I  have 
visited,  is  where  they  might  be  least  expected — viz.  Norway— not  the 
South  of  Norway  merely,  but  more  particularly  in  the  valleys  that 
slope  from  the  500  square  miles  of  the  perpetual  ice  desert  of  the 
Justedal  down  to  the  Sognefjord,  latitude  61°  to  6l£°,  considerably  j 
to  the  north  of  the  northernmost  of  the  Shetland  Islands.  The 
cherry  and  currant  trees  are  marvellous  there. 

In  the  garden  of  one  of  the  farm  stations  (Sande)  I  counted  70 
fine  bunches  of  red  currants  growing  on  six  inches  of  one  of  the 
overladen  down-hanging  stems  of  a  currant  bush.  Cherries  are 
served  for  dessert  by  simply  breaking  off  a  small  branch  of  the  tree 
and  bringing  it  to  the  table — the  fruit  almost  as  many  as  the  leaves. 

This  luxuriance  I  attribute  to  two  causes.  First,  that  in  that  part 
of  Norway  the  winter  breaks  up  suddenly  at  about  the  beginning  of 
June,  and  not  until  then,  when  night  frosts  are  no  longer  possible, 
do  the  blossoms  appear.  It  was  on  the  24th  August  that  1  counted 
the  70  bunches  of  ripe  currants.  The  second  cause  is  the  absence  of 
sparrows  and  other  destructive  small  birds  that  devour  our  currants 
for  the  seeds'  sake  before  they  ripen,  and  our  cherries  immediately 
on  ripening.  These  are  preceded  by  the  bullfinches  that  feed  on  the 
tender  hearts  of  the  buds  of  most  of  our  fruit  trees.  Those  who  be- 
lieve the  newspaper  myths  which  represent  such  thick-billed  birds 
eating  caterpillars,  should  make  observations  and  experiments  for 
themselves  as  I  have  done. 

In  our  canvas  conservatories  neither  sparrows  nor  caterpillars,  nor 
wasps,  or  other  fruit-stealers  will  penetrate,  nor  will  the  spring  frosts 
nip  the  blossoms  that  open  out  in  April.  All  the  conditions  for  full 
bearing  are  there  fulfilled,  and  the  ripening  season,  though  not  so 
intense,  will  be  prolonged.  We  shall  have  an  insular  Jersey  climate 
in  London,  where  the  mean  temperature  is  higher  than  in  the  coun- 
try around,  and,  if  I  am  not  quite  deluded,  we  shall  be  able  to  grow 
the  choicest  Jersey  pears,  those  that  best  ripen  by  hanging  on  the 
tree  until  the  end  of  December,  and  fine  peaches,  which  are  com- 
monly destroyed  by  putting  forth  their  blossoms  so  early.  All  the 
hundred-and-one  varieties  of  plums  and  damsons,  greengages,  etc., 
that  can  grow  in  temperate  climates  will  be  similarly  protected  from 
the  frosts  that  kill  their  early  blossoms,  and  the  birds  and  the  wasps 
that  will  not  give  them  time  to  ripen  slowly. 

I  have  little  doubt  that  if  my  project  is  carried  out,  any  London 
householder  whether  rich  or  poor,  may  indulge  in  delicious  desserts 
of  rich  fruit  all  grown  on  the  sites  of  their  own  now  dirty  and  deso- 
late back-yards  ;  that  if  prizes  be  given  for  the  most  prolific  branches 
of  cherry  and  plum  trees,  gooseberry  and  currant  bushes,  the  gardens 
of  the  Seven-dials  and  of  classic  St.  Giles's  may  carry  off  some  of  the 
gold  medals  ;  and  that,  by  judicious  economy  of  space  and  proper 
pruning  of  the  trees,  the  canvas  conservatories  may  be  made  not  only 
to  serve  as  orchard  houses,  but  also  to  grow  the  salads,  kitchen  herbs, 
and  green  vegetables  for  cookery  under  the  fruit  trees  or  close  around 
their  stems. 

Among  the  suitable  vegetables,  I  may  name  a  sort  of  perennial 
spinach  which  yields  a  wonderful  amount  of  produce  on  a  small  area. 

Four  years  ago  I  took  the  house  in  which  I  now  reside,  and  found 
the  garden  overgrown  with  a  weed  that  appeared  like  beet,  the  leaves 


HOME  GARDENS  FOK  SMOKY  TOWNS.  289 

being  much  larger  than  ordinary  spinach.  I  tried  in  vain  to  eradi- 
cate it,  then  gave  some  leaves  to  my  fowls.  They  ate  them  greedily. 
After  this  I  had  some  boiled,  and  found  that  the  supposed  weed  is 
an  excellent  spinach,  which  may  be  sown  broadcast  in  thick  patches, 
without  any  interspaces,  and  cut  down  again  and  again  all  the  year 
round,  fresh  leaves  springing  up  from  the  roots  until  the  autumn, 
when  it  throws  up  tall  flowering  stems,  and  yields  an  abundant  crop 
of  seeds.  I  have  some  now,  self-sown,  that  have  survived  the  whole 
of  the  late  severe  winter,  while  turnip-tops,  cabbages,  and  everything 
else  have  perished.  I  have  sown  the  ordinary  spinach  seed  in  the 
usual  manner  in  rows,  and  comparing  it  with  the  self-sown  dense 
patches  of  this  intruder,  find  the  latter  produces,  square  yard  against 
square  yard,  six  or  eight  times  as  much  of  available  eatable  crop. 

None  of  my  friends  who  are  amateur  gardeners  know  this  variety  ; 
but,  a  few  days  since,  I  called  on  Messrs.  James  Carter  &  Co.,  the 
wholesale  seedsmen  of  Holborn,  and  described  it.  They  gave  me  a 
packet  of  what  they  call  "  Perpetual  spinach  beet,"  which,  as  may  be 
seen  by  comparison  with  the  seeds  of  those  I  have  here  of  my  own 
growing,  is  probably  the  same.  Messrs.  Carter  &  Co.  tell  me  that  the 
plant  is  very  little  known,  and  the  seed  scarce  from  want  of  cultiva- 
tion and  demand.  I  therefore  step  so  far  aside  to  describe  and 
recommend  it  as  specially  suited  for  obtaining  large  crops  on  small 
areas.* 

I  also  recommend  a  mode  of  growing  cabbages  that  I  have  found 
very  profitable,  viz.,  to  sow  the  seed  broadcast  in  richly  manured 
beds  or  patches  and  leave  the  plants  crowding  together  ;  cut  them 
down  while  very  young,  without  destroying  the  centre  bud  ;  let  them 
sprout  again  and  again.  They  thus  yield  a  succession  of  crops,  every 
leaf  of  which  is  eatable.  This,  instead  of  transplanting  and  growing 
large  plants,  which,  however  desirable  for  sale  in  the  market,  are  far 
less  profitable  for  home  use.  Celery  may  be  grown  in  like  manner, 
and  cut  down  young  and  green  for  boiling. 

Some  collateral  advantages  may  be  fairly  anticipated  in  cases  where 
the  back-yard  is  fully  inclosed  by  the  canvas. 

In  the  first  place,  the  air  coming  into  the  house  from  the  back  will 
be  more  or  less  filtered  from  the  grimy  irritant  particles  with  which 
our  London  atmosphere  is  loaded,  besides  obtaining  the  oxygen  given 
off  by  the  growing  plants,  and  the  ozone  which  recent  investigations 
have  shown  to  be  produced  where  aromatic  plants — such  as  kitchen 
herbs— are  growing.  Lavender,  which  is  very  hardy,  and  spreads 
spontaneously,  might  be  grown  for  this  purpose. 

Back-doors  might  be  left  open  for  ventilation,  without  danger  of 
intrusion  or  of  slamming  by  gusts  of  wind.  The  air  thus  admitted 
would  be  tempered  both  in  summer  and  winter.  By  wetting  the 
canvas,  which  may  easily  be  done  by  means  of  a  small  garden  engine, 
or  hand  syringe,  the  exceptionally  hot  summer  days  that  are  so 
severely  felt  in  London  might  be  moderated  to  a  considerable  extent. 
The  air  under  the  canvas  being  cooler  than  that  in  front  would  enter 
from  below,  while  the  warmer  air  would  be  pushed  upward  and  out- 
ward to  the  front. 

Although  such  conservatories  may  be  erected,  as  already  stated,  by 

*  I  tried  the  feeds  given  to  me  by  Messrs.  Carter,  and  find  them  to  produce  the 
same  plant  as  my  o\vn,  which  I  still  cultivate  very  successfully.  I  now  sow  it  in 
the  spring  as  a  kitchen  garden  border. 


290  SCIENCE   IX   SHORT   CHAPTERS. 

artisans  or  other  tenants  of  small  houses,  I  do  not  advocate  depend- 
ence on  this  ;  but,  on  the  contrary,  regard  them  as  more  properly 
constituting  landlord's  fixtures,  and  recommend  their  erection  by 
owners  of  small  house  property  in  London  and  other  large  towns.  A 
workman  who  will  pay  a  trine  extra  for  such  a  garden,  is  likely  to  be 
a  better  and  more  permanent  tenant  than  one  who  is  content  with 
the  slovenly  squalor  of  ordinary  back  premises. 

I  base  this  opinion  on  some  experience  of  holding  small  houses  in 
the  outskirts  of  Birmingham  (Talbot  Street,  Winson  Green).  These 
have  small  gardens,  while  most  of  those  around  have  none.  They 
are  held  by  weekly  tenure,  and,  during  eighteen  years,  I  have  not 
lost  a  week's  rent  from  voids  ;  the  men  who  would  otherwise  shift 
their  dwelling  when  they  change  workshops,  prefer  to  remain  and 
walk  some  distance  rather  than  lose  their  little  garden  crops  ;  and 
when  obliged  to  leave,  have  usually  found  me  another  tenant,  a 
friend  who  has  paid  them  a  small  tenant-right  premium  for  what  is 
left  in  the  garden,  or  for  the  privilege  of  getting  a  house  with  such  a 
garden. 

A  small  garden  is  one  of  the  best  rivals  to  the  fascinations  of  the 
tap-room  ;  the  strongest  argument  in  favor  of  my  canvas  conservato- 
ries, and  that  which  I  reserve  as  the  last,  is  that  they  are  likely  to 
become  the  poor  man's  drawing-room,  where  he  may  spend  his  sum- 
mer evenings,  smoke  his  pipe,  contemplate  his  growing  plants,  and 
show  them  in  rivalry  to  his  friends,  rather  than  slink  away  from  an 
unattractive  home  to  seek  the  sensual  excitements  that  ruin  so  many 
of  our  industrious  fellow-countrymen. 

As  above  stated,  I  have  not  been  able  practically  to  test  the  filter- 
ing capabilities  of  the  canvas,  owing  to  my  residence  out  of  town,  but 
since  the  above  was  written,  i.e.  on  last  Wednesday  evening,  I  visited 
the  Houses  of  Parliament,  where,  as  I  had  been  told,  the  ventilation 
arrangements  include  some  devices  for  filtering  the  air  by  cotton  wool 
or  otherwise. 

I  was  much  interested  on  finding  that  the  long  experience  and 
many  trials  of  Dr.  Percy  and  his  assistant  engineer,  Mr.  Prim,  have 
resulted  in  the  selection  of  the  identical  material  which  I  have 
chosen,  and  with  which  the  above-described  experiments  have  been 
made.  A  wall  of-  such  canvas  surrounds  a  lower  region  of  the 
houses,  and  all  the  air  that  is  destined  to  have  the  privilege  of  being 
breathed  by  British  legislators  is  passed  through  this  vertical  screen, 
for  the  purpose  of  separating  from  it  the  sooty  impurities  that  con- 
stitute the  special  abomination  of  our  metropolitan  atmosphere,  and 
that  of  our  great  manufacturing  towns.  The  quantity  of  sooty  matter 
thus  arrested  is  shown  by  the  fact  that  it  is  found  necessary  to  take 
the  screens  down  once  a  week  and  wash  them,  the  wash  water  coming 
away  in  a  semi-inky  condition. 

I  anticipate  that  the  conservatory  filters  will  rapidly  clog,  and, 
therefore,  require  washing.  This  may  easily  be  done  by  means  of  a 
jet  from  a  hand-syringe  directed  from  within  outward,  especially  if 
the  slope  of  the  roof  is  considerable,  which  is  to  be  recommended. 
The  filtering  screen  of  the  Houses  of  Parliament  is  made  by  sewing 
the  canvas  edges  together,  to  form  a  large  continuous  area,  then 
edging  the  borders  of  this  with  tape,  and  stretching  it  bodily  on  to  a 
stout  frame.  This  method  may  be  found  preferable  to  that  which  I 
proposed  above,  and  cheaper  than  I  have  estimated,  as  only  very 


HOME   GARDENS   FOR   SMOKY   TOWNS.  291 

light  intermediate  cross-pieces  would  thus  be  required,  merely  to 
prevent  bagging,  the  parliamentary  quartering  above  described  being 
nine  feet  apart  instead  of  three.  This  would  reduce  the  cost  of  tim- 
ber to  about  one  half  of  the  above  estimate.*  The  perpendicular 
walls  of  a  conservatory,  where  such  are  required,  may  certainly  be 
made  thus,  and  I  think  the  roof  also,  if  the  slope  is  considerable. 
Or,  if  in  demand,  the  material  may  be  made  of  greater  width  than  the 
three  feet. 

So  far,  I  have  only  mentioned  back-yards  ;  but,  besides  these, 
there  are  many  very  melancholy  front  areas,  called  "gardens,"  at- 
tached to  good  houses  in  some  of  the  once  suburban,  but  now  inter- 
nal regions  of  London,  where  the  houses  stand  some  distance  back 
from  the  formerly  rural  highway.  These  spaces  might  be  cheaply 
inclosed  with  canvas,  and  cultivated  as  kitchen  gardens,  orchard 
houses,  flower  gardens,  or  ferneries,  thus  forming  elegant,  refreshing, 
and  profitable  vestibules  between  the  highway  and  the  house-door, 
and  also  serve  as  luxurious  summer  drawing-rooms.  The  only  objec- 
tion I  foresee  to  these  bright  inclosures  will  be  their  tendency  to 
encourage  the  consumption  of  tobacco. 

The  Discussion  which  followed  the  reading  of  the  preceding  paper  at  the 
Society  of  Arts. 

A  member  asked  if  Mr.  Williams  had  observed  the  effect  of  wind 
and  rain  on  this  material  ? 

Mr.  W.  P.  B.  Shepheard  said  he  was  interested  in  a  large  square  in 
London,  and  he  had  hoped  to  hear  something  about  the  cultivation 
of  flowers  in  such  places.  Last  year,  they  tried  the  experiment  with 
several  varieties  of  flower  seeds,  and  they  came  up  and  bloomed  well 
in  the  open  ground  without  any  protection  whatever.  In  most  Lon- 
don squares,  the  difficulty  was  to  find  any  one  bold  enough  to  try  the 
experiment  at  all,  and  nothing  but  experience  would  prove  what 
flowers  would  succeed  and  what  would  not.  They  were  so  success- 
ful last  year  that  several  fine  bouquets  were  gathered  in  July  and 
August,  and  sent  to  some  of  the  gardening  magazines,  who  expressed 
their  astonishment  that  such  good  results  were  possible  in  the  cir- 
cumstances. If  flowers  would  answer,  there  would,  of  course,  be 
more  encouragement  to  try  vegetables.  One  of  the  practical  diffi- 
culties which  occurred  to  him,  with  regard  to  this  plan,  was  that  the 
screens  would  be  somewhat  unsightly,  and  then  again  they  might 
shrink,  from  alteration  in  the  temperature  and  getting  wet  and  dry. 
He  would  repeat,  however,  that,  for  a  very  small  expense  in  seeds,  a 
very  good  show  of  hardy  annuals  and  perennials  might  be  obtained 
in  July  and  August  even  in  London. 

Mr.  C.  Cooke  said  a  flower-garden  had  recently  been  opened  in 
Drury  Lane  on  the  site  of  an  old  churchyard,  to  which  children  were 
admitted  ;  and  he  wished  a  similar  arrangement  might  be  made  in 
some  of  the  squares  in  crowded  neighborhoods,  such  as  Golden 
Square,  and  especially  in  Lincoln's  Inn  Fields.  There  were  lots  of 
children  playing  about  in  the  streets,  and  he  wished  the  good  exam- 
ple set  by  the  Templars  might  be  followed. 

*  Subsequent  experiments  induce  me  not  to  recommend  this  economy,  on  account 
of  the  bairging  which  results  from  excessive  width  between  the  frames ;  3  feet 
should  not  be  exceeded. 


292  SCIENCE   IN   SHORT   CHAPTERS. 

Mr.  Liggius,  as  an  old  member  of  the  Royal  Horticultural  Society, 
felt  a  great  interest  in  this  subject.  Among  his  poorer  neighbors  in 
the  district  of  Kensington,  cottage  and  window  gardening  had  been 
encouraged  for  some  years  past,  prizes  having  been  awarded  to  those 
who  were  most  successful,  much  to  their  gratification.  This  was  a 
novel  idea,  but  he  felt  quite  sure  that  it  would  enable  those  who  adopt- 
ed it  to  obtain  the  crops  which  had  been  described.  There  were  many 
collateral  advantages  which  it  would  bestow  on  the  working-classes 
if  largely  followed  by  them,  especially  the  one  mentioned  by  Mr. 
Williams,  that  those  who  devoted  their  spare  time  to  the  cultivation 
of  fruit  and  flowers  would  not  be  so  open  to  the  attractions  of  the 
public-house.  When  travelling  through  the  United  States  some  years 
ago,  he  was  much  struck  with  the  difference  in  appearance  of  the 
houses  in  districts  where  the  Maine  liquor  law  was  in  force,  and  soon 
learned  to  distinguish  where  it  was  adopted,  by  the  clean,  cheerful 
look  of  the  workmen's  dwellings,  the  neatness  of  the  gardens,  and 
the  presence  of  trees  and  flowers  which,  in  other  districts,  were 
wanting.  He  was  not  a  teetotaller  himself,  and  was  not  advocating 
such  restrictions,  but  he  could  not  help  noticing  the  contrast  ;  and 
he  felt  sure  that  in  all  our  large  towns  great  progress  in  civilization 
and  morals  would  be  effected  if  such  an  attraction  were  offered  to 
the  working- classes.  He  believed  there  was  so  much  intelligence  and 
good  sense  among  them,  that  if  they  only  knew  what  could  be  done 
in  this  way  they  would  attempt  it  ;  and  when  an  Englishman  at- 
tempted anything  he  generally  succeeded. 

Mr.  William  Botly  said  they  were  much  indebted  to  Mr.  Williams 
for  having  called  attention  to  this  important  subject.  He  quite 
agreed  with  the  observations  of  the  last  speaker,  for  his  own  experi- 
ence in  building  cottages  showed  him  that  the  addition  of  a  piece  of 
garden  ground  had  an  excellent  effect  on  the  social,  moral,  and 
religious  welfare  of  the  inmates.  It  kept  them  from  the  public- 
house,  and  the  children  who  were  brought  up  to  hoe  and  weed  their 
parents'  gardens  turned  out  the  most  industrious  laborers  on  his 
property.  He  had  known  of  instances  where  houses  had  been  built 
with  flat  concrete  roofs,  and  covered  in  with  glass,  so  as  to  form  a 
conservatory,  in  which  vegetables  and  salads  grow  very  well,  and  he 
believed  the  cost  was  little,  if  any,  more  than  ordinary  slating. 

The  Chairman  (Lord  Alfred  Churchill)  in  moving  a  vote  of  thanks 
to  Mr.  Williams,  said  there  could  be  no  doubt  that  if  his  suggestion 
were  adopted  it  would  lead  to  great  economy,  and  have  many  other 
attractions  for  the  working-classes.  During  the  last  few  years  they 
had  heard  a  good  deal  about  floriculture  in  windows,  and  no  doubt  it 
was  an  excellent  proposal,  but  if  they  could  add  to  this  the  growth  of 
vegetables,  it  would  have  economical  advantages  also.  The  proposal 
to  erect  temporary  conservatories  on  the  roofs  of  some  of  these  small 
houses  was  an  admirable  one.  He  saw  no  reason  why  you  should 
not  have  a  peach-tree  growing  against  many  a  tall  chimney  ;  you 
would  only  want  a  metal-lined  tub  filled  with  good  mould  ;  the 
warmth  of  the  chimney  would  aid  in  promoting  the  growth  of  the 
tree,  and  it  could  be  protected  from  the  smoke  and  frost  by  this 
canvas.  One  point  he  should  like  to  know  was,  whether  the  fabric 
would  not  become  rotted  by  the  weather,  and  perhaps  it  might  be 
protected  by  tanning,  or  some  chemical  preparation.  The  effect  of 
the  canvas  in  maintaining  an  equable  temperature  was  a  great  con- 


HOME    GARDENS    FOR    SMOKY   TOWXS.  293 

side  ration  ;  the  difference  stated  by  Mr.  Williams,  of  about  five  de- 
grees in  winter,  in  many  cases  would  be  just  enough  to  save  the  life 
of  a  plant.  Practical  gardeners  knew  the  value  of  placing  a  covering 
over  a  peach-tree  in  early  spring  to  keep  off  the  frosts,  and  also  to 
protect  it  from  the  attacks  of  birds.  It  was  also  a  curious  fact  that 
even  a  slip  of  wood  or  slate  a  few  inches  wide,  put  on  the  top  of  a 
wall  to  which  a  fruit  tree  was  nailed,  acted  as  a  protection  from  frost. 
He  trusted  that  Mr.  Williams'  idea  would  find  favor  among  the  work- 
ing-classes, and  thought  it  was  a  subject  the  Koyal  Horticultural 
Society  might  well  take  up  and  offer  prizes  for.  He  hoped  in  a  short 
time,  when  that  Society  had  passed  through  a  crisis  which  was  im- 
pending, it  might  emerge  in  a  condition  to  devote  attention  to  this 
matter.  It  already  offered  prizes  for  small  suburban  flower-shows, 
but  had  not  yet  turned  its  attention  to  the  larger  class  aimed  at  by 
Mr.  Williams. 

Mr.  Botly  said  he  had  forgotten  to  mention  that  he  had  a  friend,  a 
very  excellent  gardener,  who  always  loosened  his  fruit  trees  from  the 
wall  for  about  three  weeks  before  the  time  of  blooming.  The  conse- 
quence was,  they  did  not  get  so  much  heat  from  the  wall,  and  the 
bloom  was  two  or  three  weeks  later  in  forming.  After  the  spring 
frosts,  the  trees  were  again  nailed  up  close,  and  he  never  failed  in 
getting  an  excellent  crop,  when  his  neighbors  often  had  none. 

Mi\  Trewby  wished  to  caution  those  who  read  the  paper  against 
using  what  was  commonly  known  as  paperhangers'  canvas,  because 
it  was  made  of  two  materials,  hemp  and  jute,  and  if  a  piece  of  it  were 
put  into  water  it  would  soon  be  nothing  but  a  lot  of  strings,  the  jute 
being  all  dissolved.  It  did  very  well  for  paper-hanging,  but  would  be 
quite  unsuitable  for  this  purpose.* 

The  vote  of  thanks  having  been  passed — 

Mr.  Williams,  in  reply,  said  he  had  had  a  piece  of  this  canvas 
stretched  on  a  frame  exposed  all  the  winter,  and  the  only  result  was 
to  make  it  rather  dirty.'  He  stretched  it  as  tightly  as  he  could  in 
putting  it  on,  but  when  it  got  wet  it  became  still  more  tight,  and 
gave  a  little  again  on  becoming  dry.  It  bore  the  weight  of  the  snow 
which  had  fallen  very  well,  and  two  or  three  spadefuls  had  been 
added  to  try  it.  He  had  a  note  from  Mr.  Prim,  saying  that  at  the 
Houses  of  Parliament  the  screens  last  about  two  sessions,  being 
washed  once  a  week,  and  the  destruction  is  due  to  the  wringing. 
But  there  is  really  no  occasion  for  this,  for  if  you  syringe  the  stuff 
well  from  the  inside,  you  make  it  sufficiently  clear  to  allow  the  air 
and  light  to  pass  through  and  it  would  probably  last  many  years. 
He  had  tried  the  experiment  of  dipping  it  in  a  very  weak  solution  of 
tar,  but  this  had  the  effect  of  matting  together  the  fine  filaments,  so 
that  it  did  not  act  so  effectually  as  a  strainer.  It  acted  best  when. 
wet,  because  the  fine  particles  of  soot  adhered  to  it,  and  moist 
weather  was  jnst  the  time  when  the  greatest  quantity  of  soot  fell.  It 
might,  be  easily  tried  in  London  sqiiares  to  aid  in  the  growth  of 
flowers  ;  he  found  that  the  cabbage  plants  which  were  so  protected 
throve  remarkably  well,  and  he  had  no  doubt  that  if  flowers  were 
planted  and  a  screen  put  over  them  until  they  were  ready  to  bloom, 

*  I  have  followed  np  Mr.  Trewby's  hint,  and  find  that  more  than  one  quality  of 
scrim  is  made.  The  best,  made  entirely  of  flax,  costs  rather  more  than  the  Z^d. 
stated  in  the  estimate,  but  it  is  the  cheapest  practically.  The  best  I  have  eeeii  is 
that  used  in  the  Houses  of  Parliament. 


294  SCIENCE   IN   SHORT   CHAPTERS. 

it  would  be  a  great  advantage.  The  action  of  a  little  pent  on  the  top 
of  a  wall  to  protect  fruit  trees  is  very  simple,  and  the  explanation 
was  afforded  by  the  experiments  of  l)r.  Wells  on  dew.  The  frosts, 
which  did  the  greatest  mischief,  were  due  to  radiation  from  the 
ground  on  clear  nights  ;  and  it  would  be  found  that  if  one  thermom- 
eter were  placed  in  a  garden  under  an  umbrella,  and  another  on  the 
open  ground  near  it,  the  differences  of  temperature  would  be  very 
considerable  ;  on  cloudy  nights  there  was  very  little  difference. 
Last  night  there  was  only  a  difference  of  2°,  but  a  few  nights  before 
it  was  6°.  The  period  of  greatest  cold  might  not  probably  be  more 
than  an  hour,  but  it  would  be  sufficient  to  do  a  great  deal  of  mis- 
chief, and  anything  which  would  check  the  radiation  would  have  the 
required  effect.  In  the  case  of  loosening  the  fruit  trees  from  the 
wall  there  was,  probably,  a  double  action  ;  it  prevented  the  tree 
being  forced  on  by  the  warmth  of  the  wall  in  the  daytime,  and  also 
avoided  the  chilling  effect  at  night,  a  rough  wall  being  a  good  radia- 
tor, and  sinking  to  a  low  temperature.  He  did  not  think  there  was 
much  danger  to  be  apprehended  from  wind,  because  the  canvas  being 
so  open,  the  wind  would  pass  freely  through  it  ;  but  he  had  not  seen 
it  subjected  to  any  violent  gale. 


CHAPTER  XLIII. 

SOLIDS,    LIQUIDS,    AND    GASES. 

THE  growth  of  accurate  knowledge  is  continually  narrowing,  and 
often  obliterating,  the  broad  lines  of  distinction  that  have  been  drawn 
between  different  classes  of  things.  I  well  remember  when  our 
best  naturalists  regarded  their  "  species "  of  plants  and  animals  as 
fundamental  and  inviolable  institutions,  separated  by  well-defined 
boundaries  that  could  not  be  crossed.  Darwin  has  upset  all  this,  and 
now  we  cannot  even  draw  a  clear,  sharp  line  between  the  animal  and 
vegetable  kingdoms.  The  chemist  is  even  crossing  the  boundary 
between  these  and  the  mineral  kingdom,  by  refuting  the  once  posi- 
tive dictum  that  organic  substances  (i.e.  the  compounds  ordinarily 
formed  in  the  course  of  vegetable  or  animal  growth)  cannot  be  pro- 
duced directly  from  dead  matter  by  any  chemical  device.  Many  of 
such  organic  compounds  are  now  made  in  the  laboratory  from  mineral 
materials. 

We  all  know  broadly  what  are  the  differences  between  solids, 
liquids,  and  gases,  and,  until  lately,  they  have  been  very  positively 
described  as  the  three  distinct  states  or  modes  of  existence  of  matter. 
Mr.  Crookes  suggests  a  fourth.  I  will  not  discuss  this  at  present,  but 
merely  consider  the  three  old-established  claimants  to  distinctive 
existence. 

A  solid  is  usually  defined  as  a  body  made  up  of  particles  which  hold 
together  rigidly  or  immovably,  in  contradistinction  to  a  fluid,  of  which 
the  particles  move  freely  over  each  other.  "  Fluids  "  is  the  general 
term  including  both  gases  and  liquids,  both  being  alike  as  regards  the 
mobility  of  their  particles.  At  present,  let  us  confine  our  attention  to 
liquids  and  solids. 


SOLIDS,    LIQUIDS,    AtfD   GASES.  295 

The  theoretical  or  perfect  fluid  which  is  imagined  by  the  mathema- 
tician as  the  basis  of  certain  abstract  reasonings  has  no  real  existence. 
He  assumes  (and  the  assumption  is  legitimate  and  desirable,  pro- 
vided its  imaginary  character  is  always  remembered)  that  the  sup- 
posed particles  move  upon  each  other  with  perfect  freedom,  without 
any  friction  or  other  impediment ;  but,  as  a  matter  of  fact,  all  liquids 
exert  some  amount  of  resistance  to  their  own  flowing  ;  they  are  more 
or  less  viscous,  have  more  or  less  of  that  sluggishness  in  their  obedience 
to  the  law  of  finding  their  own  level  which  we  see  so  plainly  displayed 
by  treacle  or  castor  oil. 

This  viscosity,  added  to  the  friction  of  the  liquid  against  the  solid 
on  which  it  rests,  or  in  which  it  is  enclosed,  may  become,  even  in  the 
case  of  water,  a  formidable  obstacle  to  its  flow.  Thus,  if  wre  make  a 
hole  in  the  side  of  a  tank  at  a  depth  of  16  feet  below  the  surface,  the 
water  will  spout  from  that  hole  at  the  rate  of  32  feet  per  second,  but 
if  we  connect  with  this  hole  a  long  horizontal  pipe  of  the  same  inter- 
nal diameter  as  the  hole,  and  then  observe  the  flow  from  the  outlet  of 
the  pipe,  we  shall  find  its  velocity  visibly  diminished,  and  we  shall 
be  greatly  deceived  if  we  make  arrangements  for  carrying  swift-flow- 
ing water  thus  to  any  great  distances. 

Three  or  four  years  ago  an  attempt  was  made  to  supersede  the  water- 
carts  of  London  by  laying  down  on  each  side  of  the  road  a  horizontal 
pipe,  perforated  with  a  row  of  holes  opening  towards  the  horse-way. 
The  water  wus  to  be  turned  on,  and  from  these  holes  it  was  to  jet  out 
to  the  middle  of  the  road  from  each  side,  and  thus  water  it  all.  I 
watched  the  experiment  made  near  the  Bank  of  England. 

Instead  of  spouting  across  the  road  from  all  these  holes,  as  it  would 
have  done  from  any  one  of  them,  it  merely  dribbled  ;  the  reason  being 
that,  in  order  to  supply  them  all,  the  water  must  run  through  the 
whole  of  the  long  pipe  with  considerable  velocity,  and  the  viscosity 
and  friction  to  be  overcome  in  doing  this  nearly  exhausted  the  whole 
force  of  water-head  pressure.  Many  other  similar  blunders  have  been 
made  by  those  who  have  sought  to  convey  water-power  to  a  distance 
by  means  of  a  pipe  of  such  diameter  as  should  demand  a  rapid  flow 
through  a  long  pipe. 

The  resistance  which  water  offers  to  the  stroke  of  the  swimmer  or 
the  pull  of  the  rower  is  partly  due  to  its  viscosity,  and  partly  to  the 
uplifting  or  displacement  of  some  of  the  water.  If  it  were  perfectly 
fluid,  our  movements  within  it,  and  those  of  fishes,  etc.,  would  be 
curiously  different ;  the  whole  face  of  this  globe  would  be  strangely 
altered  in  many  respects. 

I  will  not  now  follow  up  this  idea,  but  leave  it  as  a  suggestion  for 
the  reader  to  work  out  for  himself,  by  considering  what  would  remain 
undone  upon  the  earth  if  water  flowed  perfectly,  without  any  inter- 
nal resistance,  or  friction  upon  the  earth's  surface. 

The  degrees  of  approach  to  perfect  fluidity  vary  greatly  with  dif- 
ferent liquids. 

Is  there  any  such  a  thing  as  an  absolute  solid,  or  a  body  that  has  no 
degree  of  fluidity,  the  particles  or  parts  of  which  will  admit  of  no 
change  of  their'  relative  positions,  no  movement  upon  each  other 
without  fracture  of  the  mass  ?  This  would  constitute  perfect  rigidity, 
or  the  opposite  to  fluidity. 

Take  a  piece  of  copper  or  soft  iron-wire,  about  one  eighth  of  an 
inch  in  diameter,  or  thereabout,  and  bend  it  backward  and  forward 


296  SCIENCE   IN   SHOUT   CHAPTERS. 

a  few  times  as  rapidly  as  possible,  but  without  breaking  it ;  then, 
without  loss  of  time,  .feel  the  portion  that  has  been  bent.  It  is  hot- 
painfully  so— if  the  experiment  is  smartly  made.  How  may  this  be 
explained  ? 

It  is  evident  that  in  the  act  of  bending  there  must  have  been  a  dis- 
placement of  the  relative  positions  of  the  particles  of  the  metal,  and 
the  force  demanded  for  the  bending  indicated  their  resistance  to  this 
movement  upon  each  other  ;  or,  in  other  words,  that  there  was 
friction  between  them,  or  something  equivalent  to  such  internal 
friction,  and  thus  the  mechanical  force  exerted  in  the  bending  was 
converted  into  heat-force. 

Here,  then,  was  fluidity,  according  to  the  above  definition  ;  not 
perfect  fluidity,  but  fluidity  attended  with  resistance  to  flow,  or  what 
we  have  agreed  to  call  viscosity.  But  water  also  offers  such  resist- 
ance to  flow  or  viscosity,  therefore  the  difference  between  iron  or 
copper  wire  and  liquid  water  as  regards  their  fluidity  is  only  a  dif- 
ference of  degree,  and  not  of  kind  ;  the  demarcation  between  solids 
and  liquids  is  not  a  broad,  clearly-defined  line,  but  a  band  of  blend- 
ing shade,  the  depths  of  tint  representing  varying  degrees  of  vis- 
cosity. 

Multitudes  of  examples  may  be  cited  illustrating  the  viscosity  of 
bodies  that  we  usually  regard  as  types  of  solidity,  such,  for  example, 
as  the  rocks  forming  the  earth's  crust.  In  the  "Black  Country"  of 
South  Staffordshire,  which  is  undermined  by  the  great  ten-yard  coal- 
seam,  cottages,  chimney-shafts,  and  other  buildings  may  be  seen  lean- 
ing over  most  grotesquely,  houses  split  down  the  middle  by  the  sub- 
sidence or  inclination  of  one  side,  great  hollows  in  fields  or  across 
roads  that  were  once  flat,  and  a  variety  of  other  distortions,  due  to 
the  gradual  sinking  of  the  rock-strata  that  have  been  undermined  by 
the  colliery  workings.  In  some  cases  the  rocks  are  split,  but  usually 
the  subsidence  is  a  bending  or  flowing  down  of  the  rocks  to  fill  up 
the  vacuity,  as  water  fills  a  hollow,  or  "  finds  its  own  level." 

I  have  seen  many  cases  of  the  downward  curvature  of  the  roof  of 
ft  coal-pit,  and  have  been  told  that  in  some  cases  the  surrounding 
pressure  causes  the  floor  to  curve  upward,  but  have  not  seen  this. 

Earthquakes  afford  another  example.  The  so-called  solid  crust  of 
the  earth  is  upheaved,  and  cast  into  positive  billows  that  wave  away 
on  all  sides  from  the  centre  of  disturbance.  The  earth  billows  of  the 
great  Lisbon  earthquake  of  1755  travelled  to  this  country,  and  when 
they  reached  Loch  Lomond,  were  still  of  sufficient  magnitude  to  raise 
and  lower  its  banks  through  a  perpendicular  range  of  two  feet  four 
inches. 

It  is  quite  possible,  or,  I  may  say,  probable,  that  there  are  tides  of 
the  earth  as  well  as  of  the  waters,  and  the  subject  has  occupied  much 
attention  and  raised  some  discussion  among  mathematicians.  If  the 
earth  has  a  fluid  centre,  and  only  a  comparatively  thin  crust,  as  some 
suppose,  there  must  be  such  tides,  produced  by  the  gravitation  of  the 
moon  and  sun. 

Ice  presents  some  interesting  results  of  this  viscosity.  At  a  certain 
height,  varying  with  latitude,  aspect,  etc.,  we  reach  "the  snow-line  " 
of  mountain  slopes,  above  which  the  snow  of  winter  remains  unmelted 
during  summer,  and,  in  most  cases,  goes  on  accumulating.  It  soon 
loses  its  flocculent,  flaky  character,  and  becomes  coherent,  clear  blue 
ice  by  the  pressure  of  its  own  weight. 


SOLIDS,    LIQUIDS,    AND   GASES.  297 

A  rather  complex  theory  has  been  propounded  to  explain  this 
change  — the  theory  of  revelation —  i.e.  re-freezing  ;  a  theory  which 
assumes  that  the  pressure  first  thaws  a  film  of  ice  at  the  surfaces  of 
contact,  and  that  presently  this  re-freezes,  and  thus  effects  a  healing 
or  general  solidification.  Faraday  found  that  two  pieces  of  ice  with 
moistened  surfaces  united  if  pressed  together  when  at  just  about  the 
temperature  of  freezing,  but  not  if  much  colder.  Tyndall  has  further 
illustrated  this  by  taking  fragments  of  ice  and  squeezing  them  in  a 
mould,  whereby  they  became  a  clear,  transparent  ball,  or  cake. 
Schoolboys  did  the  like  long  before,  when  snowballing  with  snow  at 
about  the  thawing  point.  Such  snow,  as  we  all  remember,  became 
converted  into  stony  lumps  when  firmly  pressed  together.  We  also 
remember  that  in  much  colder  wreather  no  such  cohesion  occurred, 
but  our  snowballs  remained  powdery  in  spite  of  all  our  squeezing. 

I  am  a  sceptic  as  regards  this  theory  of  regelation.  I  believe  that 
the  true  explanation  is  much  simpler  ;  that  the  crystals  of  snow  or 
fragments  of  ice  in  these  experiments  are  simply  welded,  as  the  smith 
unites  two  pieces  of  iron,  by  merely  pressing  them  together  when  they 
are  near  their  melting  point.  Other  metals  and  other  fusible  sub- 
stances may  be  similarly  welded,  provided  they  soften  or  become 
sufficiently  viscous  before  fusing. 

Platinum  is  a  good  example  of  this.  It  is  infusible  in  ordinary  fur- 
naces, but  becomes  pasty  before  melting,  and,  therefore,  one  method 
adopted  in  the  manufacture  of  platinum  ingots  or  bars  from  the 
ore  is  to  precipitate  a  sort  of  platinum  snow  (spongy  platinum) 
from  its  solution  in  acid,  and  then  compress  this  metallic  snow  in 
red-hot  steel  moulds  by  means  of  pistons  driven  with  great  force. 
The  flocculent  metal  thus  becomes  a  solid,  coherent  mass,  just  as  the 
flocculent  ice  became  coherent  ice  in  Tyndall's  experiment  or  in 
making  hard  snowballs. 

Wax,  pitch,  resin,  and  all  other  solids  that  fuse  gradually,  cohere, 
are  weldable,  or,  in  very  plain  language,  "  stick  together, "  when  near 
their  fusing  point. 

I  have  made  the  following  experiment  to  prove  that  when  this  so- 
called  regelation  of  snow  or  ice-fragments  occurs,  the  ice  is  viscous 
or  plastic,  like  wax  or  pitch.  A  strong  iron  squirt,  with  a  cylindrical 
bore  of  half  an  inch  in  diameter,  is  fitted  with  an  iron  piston.  This 
piston  is  driven  forth  by  a  screw  working  in  a  collar  at  one  end  of 
the  squirt.  Into  the  other  end  is  screwed. a  brass  nozzle  with  an 
aperture  about  one  twentieth  of  an  inch  diameter,  tapering  or  open- 
ing inward  gradually  to  the  half-inch  bore. 

Into  this  bore  I  place  snow  or  fragments  of  ice,  then  holding  the 
body  of  the  squirt  firmly  in  a  vise,  I  work  the  lever  of  the  screw,  and 
thus  drive  forward  the  piston  and  crush  down  the  snow  or  ice-frag- 
ments, which  presently  become  coherent  and  form  a  half -inch  solid 
cylinder  of  clear  ice.  Applying  still  more  pressure,  this  cylinder  is 
forced  like  a  liquid  through  the  small  orifice  of  the  nozzle  of  the  squirt, 
and  it  jets  or  spouts  out  as  a  thin  stick  of  ice  like  vermicelli,  or  the 
"leads"  of  ever-pointed  pencils,  for  the  moulding  of  which  the 
squirt  was  originally  constructed. 

I  find  that  ice  at  32°  can  thus  be  squirted  more  easily  than  bees- 
wax of  the  same  temperature,  and  such  being  the  case,  I  see  no 
reason  for  imagining  any  complex  operation  of  regelation  in  the  case 
of  the  ice,  but  merely  regard  the  adhesion  of  two  pieces  of  ice  when 


298  SCIENCE   IN   SHORT   CHAPTERS. 

pressed  together  as  similar  to  the  sticking  together  of  two  pieces  of 
cobblers'  wax,  or  softened  sealing-wax,  or  beeswax,  or  the  welding  of 
iron  or  glass  when  heated  to  their  welding  temperatures — i.e.  to  a 
certain  degree  of  incipient  fluidity  or  viscosity. 

If  a  leaden  bullet  be  cut  in  half,  and  the  two  fresh-cut  faces 
pressed  forcibly  together,  they  cohere  at  ordinary  atmospheric  tem- 
peratures, but  we  have  no  occasion  for  a  regelation  theory  here.  The 
viscosity  of  the  lead  accounts  for  all.  At  Woolwich  Arsenal  there  is  a 
monster  squirt,  similar  to  my  little  one.  This  is  charged  with  lead, 
and,  by  means  of  hydraulic  pressure,  the  lead  is  squirted  out  of  the 
nozzle  as  a  cylindrical  jet  of  any  required  diameter.  This  jet  or 
stick  of  lead  is  the  material  of  which  the  elongated  cylindrical  rifle 
bullets  are  now  made. 

But  returning  to  the  point  at  which  we  started,  on  the  subject  of 
ice— viz.  its  Alpine  accumulation  above  the  snow-line.  If  the  snow- 
fall there  exceeds  the  amount  that  is  thawed  and  evaporated,  it  must 
cither  go  on  growing  upward  until  it  reaches  the  highest  atmospheric 
region  from  which  it  falls,  or  is  formed,  or  it  must  descend  some- 
how. 

If  ice  can  be  squirted  through  a  syringe  by  mere  hand-pressure,  we 
are  justified  in  expecting  that  it  would  be  forced  down  a  hill  slope,  or 
through  a  gully,  or  across  a  plain,  by  the  pressure  of  its  own  weight 
when  the  accumulation  is  great.  Such  is  the  case,  and  thus  are 
glaciers  formed. 

They  are,  strictly  speaking,  rivers  or  torrents  of  ice  ;  they  flow  as 
liquid  water  does,  and  down  the  same  channels  as  would  carry  the 
liquid  surface  drainage  of  the  hills,  were  rain  to  take  the  place  of 
snow.  Like  rivers,  they  flow  with  varying  speed,  according  to  the 
slope  ;  like  rivers,  their  current  is  more  rapid  in  the  middle  than  the 
sides  ;  like  rivers,  they  exert  their  greatest  tearing  force  when 
squeezed  through  narrow  gullies  ;  and,  like  rivers,  they  spread  out 
into  lakes  when  they  come  upon  an  open  basin-like  valley,  with  nar- 
row outlet. 

The  Justedalsbrae  of  Norway  is  a  great  ice-lake  of  this  character, 
covering  a  surface  of  about  500  square  miles,  and  pouring  down  its 
ice-torrents  on  every  side,  wherever  there  is  a  notch  or  valley  de- 
scending from  the  table-land  it  covers.  The  rate  of  flow  of  such 
downpouring  glaciers  varies  from  two  or  three  inches  to  as  many  feet 
per  day,  and  they  present  magnificent  examples  of  the  actual  fluidity 
or  viscosity  of  an  apparently  solid  mass.  This  viscosity  has  been 
disputed,  and  attempts  have  been  made  to  otherwise  explain  the 
motion  of  glaciers  ;  but  while  it  is  possible  that  it  may  be  assisted  by 
varying  expansion  and  contraction,  the  downflow  due  to  viscosity  is 
now  recognized  as  unquestionably  the  main  factor  of  glacier  motion. 

Cascades  of  ice  may  be  sometimes  seen.  In  the  course  of  my  first 
visit  to  Norway,  I  wandered  alone  over  a  very  desolate  mountain 
region  toward  the  head  of  the  Justedal,  and  unexpectedly  came  upon 
a  gloomy  lake,  the  Styggevand,  which  lies  at  the  foot  of  a  precipice- 
boundary  of  the  great  ice-field  above  named.  Here,  the  ice  having 
no  sloping  valley-trough  by  which  to  descend,  poured  over  the  edge 
of  the  precipice  as~a  great  overhanging  sheet  or  cornice,  which  bent 
down  as  it  was  pushed  forward,  and  presented  on  the  convex  side  of 
the  sheet  some  fine  blue  cracks,  or  "  crevasses"  as  they  are  called. 
These  gradually  widened  and  deepened,  until  the  overhanging  mass 


SOLIDS,    LIQUIDS,    AND    GASES.  299 

broke  off  and  fell  into  the  lake,  on  the  surface  of  which  I  saw  the 
result,  in  the  form  of  several  floating  icebergs  that  had  previously 
fallen. 

Something  like  this,  on  a  small  scale,  may  be  seen  at  home  on  the 
edge  of  a  house  roof,  on  which  there  has  been  an  accumulation  of 
snow  ;  but,  in  this  case,  it  is  rather  sliding  than  flowing  that  has 
made  the  cornice  ;  but  its  down-bending  is  a  result  of  viscosity. 

These  and  a  multitude  of  other  facts  that  might  be  stated,  many  of 
which  will  occur  to  the  reader,  prove  clearly  enough  that  the  solid 
and  liquid  states  of  matter  are  not  distinctly  and  broadly  separable, 
but  are  connected  by  an  intermediate  condition  of  viscosity. 

We  now  come  to  the  question  whether  there  is  any  similar  conti- 
nuity between  liquids  and  gases.  Ordinary  experience  decidedly  sug- 
gests a  negative  answer.  We  can  point  to  nothing  within  easy  reach 
that  has  the  properties  of  a  liquid  and  gaseous  half -end-half  ;  that 
stands  between  gases  and  liquids  as  pitch  and  treacle  stand  between 
solids  and  liquids. 

Some,  perhaps,  may  suggest  that  cloud-matter — London  fog,  for 
example  —is  in  such  an  intermediate  state.  This,  however,  is  not  the 
case.  White  country  fog,  ordinary  clouds,  or  the  so-called  "  steam" 
that  is  seen  assuming  cloud  forms  as  it  issues  from  the  spout  of  a 
tea-kettle  or  funnel  of  a  locomotive,  consists  of  minute  particles  of 
water  suspended  in  air,  as  solid  particles  of  dust  are  also  suspended. 
It  has  been  called  "  vesicular  vapor,"  on  the  supposition  that  it  has 
the  form  of  minute  vesicles,  like  soap-bubbles  on  a  very  small  scale, 
but  this  hypothesis  remains  unproven.  London  fog  consists  of 
similar  particles,  varnished  with  a  delicate  film  of  coal-tar,  and  inter- 
sprinkled  with  particles  of  soot. 

In  order  to  clearly  comprehend  the  above-stated  question,  we  must 
define  the  difference  between  liquids  and  gases.  In  the  first  place, 
they  are  both  fluids,  as  already  agreed.  What,  then,  is  the  essential 
difference  between  liquid  fluidity  and  gaseous  fluidity?  The  expert 
in  molecular  mathematics,  discoursing  to  his  kinematical  brethren, 
would  produce  a  tremendous  reply  to  this  question.  He  would  de- 
scribe the  oscillations,  gyrations,  collisions,  mean  free  paths,  and 
mutual  obstructions  of  atoms  and  molecules,  and,  by  the  aid  of  a 
maddening  array  of  symbols,  arrive  at  the  conclusion  that  gases, 
unless  restrained,  expand  of  their  own  accord,  while  liquids  retain 
definite  limits  or  dimensions. 

The  matter-of-fact  experimentalist  demonstrates  the  same  by 
methods  that  are  easily  understood  by  anybody.  I  shall,  therefore, 
both  for  my  own  sake  and  my  readers',,  describe  some  of  the  latter. 

In  the  first  place,  we  all  see  plainly  that  liquids  have  a  surface,  i.e., 
a  well-defined  boundary,  and  also  that  gases,  unless  inclosed,  have 
not.  But  as  this  may  be  due  to  the  invisibility  of  the  gas,  we  must 
question  it  further.  The  air  we  breathe  may  be  taken  as  a  type  of 
gases,  as  water  may  of  liquids.  It  has  weight,  as  we  may  prove  by 
weighing  a  bottle  full  of  air,  then  pumping  out  the  contents,  weigh- 
ing the  empty  bottle,  and  noting  the  difference. 

Having  weight,  it  presses  toward  the  earth,  and  is  squeezed  by  all 
that  rests  above  it  ;  thus  the  air  around  us  is  constrained  air.  It  is 
very  compressible,  and  is  accordingly  compressed  by  the  weight  of  all 
the  air  above  it. 

This  being  understood,  let   us  take  a  bottle  full  of  water  and 


300  SCIENCE   IK   SHORT   CHAPTERS. 

another  full  of  air,  and  carry  them  both  to  the  summit  of  Mont 
Blanc,  or  to  a  similar  height  in  a  balloon.  We  shall  then  have  left 
nearly  half  of  the  atmosphere  below,  and  thus  both  liquid  and  gas 
will  be  under  little  more  than  half  of  the  ordinary  pressure.  What 
will  happen  if  we  uncork  them  both  ?  The  liquid  will  still  display 
its  definite  surface,  and  remain  in  the  bottle,  but  not  so  the  gas.  It 
will  overflow  upward,  downward,  or  sideways,  no  matter  how  the  bot- 
tle is  held,  and  if  we  had  tied  an  empty  bladder  over  the  neck  before 
uncorking,  we  should  find  this  overflow  or  expansion  of  the  gas 
exactly  proportionate  to  the  removal  of  pressure,  provided  the  tem- 
perature remained  unaltered.  Thus,  at  just  half  the  pressure  under 
which  a  pint  bottle  was  corked,  the  air  would  measure  exactly  one 
quart,  at  one  eighth  of  the  pressure  one  gallon,  and  so  on. 

We  cannot  get  high  enough  for  the  latter  expansion,  but  can  easily 
imitate  the  effect  of  further  elevation  by  means  of  an  air-pump. 
Thus,  we  may  put  one  cubic  inch  of  air  into  a  bladder  of  100  cubic 
inches  capacity,  then  place  this  under  the  receiver  of  an  air-pump, 
and  reduce  the  pressure  outside  the  bladder  to  T^th  of  its  original 
amount.  With  such  atmospheric  surrounding,  the  one  cubic  inch  of 
air  will  plump  out  the  flaccid  bladder,  and  completely  fill  it.  The 
pumpability  of  the  air  from  the  receiver  shows  that  it  goes  on  over- 
flowing from  it  into  the  piston  of  the  pump  as  fast  as  its  own  elastic 
pressure  on  itself  is  diminished. 

Numberless  other  experiments  may  be  made,  all  proving  that  all 
gases  are  composed  of  matter  which  is  not  merely  incohesive,  but  is 
energetically  self-repulsive  ;  so  much  so,  that  it  can  only  be  retained 
within  any  bounds  whatever  by  means  of  some  external  pressure  or 
constraint.  For  aught  we  know  experimentally,  the  gaseous  contents 
of  one  of  Mr.  Glaisher's  balloons  would  outstretch  itself  sufficiently 
to  occupy  the  whole  sphere  of  space  that  is  spanned  by  the  earth's 
orbit,  provided  that  space  were  perfectly  vacuous,  and  the  balloon 
were  burst  in  the  midst  of  it,  the  temperature  of  the  expanding  gas 
being  maintained. 

Here,  then,  in  this  self-repulsiveness,  instead  of  self-cohesion,  thif 
absence  of  self-imposed  boundary  or  dimensions,  we  have  a  veiy 
broad  and  well-marked  distinction  between  gases  and  liquids,  so 
broad  that  there  seems  no  bridge  that  can  possibly  cross  it.  This 
was  believed  to  be  the  case  until  recently.  Such  a  bridge  has,  how- 
ever, been  built,  and  rendered  visible,  by  the  experimental  re^Garches 
of  Dr.  Andrews  ;  but  further  explanation  is  required  to  render  this 
generally  intelligible. 

Until  quite  lately  it  was  customary  to  divide  gases  into  two 
classes— "  permanent  gases"  and  "  condensable  gus^s"  or"  vapors." 
Gaseous  water  or  steam  was  usually  described  as  typical  of  the 
latter  ;  oxygen,  hydrogen,  or  nitrogen  of  the  former.  Earlier  than 
this,  many  other  gases  were  included  in  the  permanent  list  ;  but 
Faraday  made  a  serious  inroad  upon  this  classification  when  he 
liquefied  chlorine  by  cooling  and  compressing  it.  Long  after  this, 
the  gaseous  elements  of  water,  and  the  chief  constituents  of  air, 
oxygen,  hydrogen,  and  nitrogen,  resisted  all  efforts  to  conden.se 
them  ;  but  now  they  have  succumbed  to  great  pressure  and  .extreme 
cooling. 

We  thus  arrive  at  a  very  broad  generalization— viz.,  that  all  gases 
are  physically  similar  to  steam  (I  mean,  of  course,  "  dry  steam/'  /.«., 


SOLIDS,    LIQUIDS,    AND   GASES.  301 

true  invisible  steam,  and  not  the  cloudy  matter  to  -which  the  name 
of  steam  is  popularly  given),  that  they  are  all  formed  by  raising 
liquids  above  their  boiling-point,  just  as  steam  is  formed  when  we 
boil  water  and  maintain  the  steam  above  the  boiling-point  o£  the 
water. 

But  some  liquids  boil  at  temperatures  far  below  that  at  which 
others  freeze  ;  liquid  chlorine  boils  at  a  temperature  below  that  of 
freezing  water,  liquid  carbonic  acid  below  even  that  of  freezing  mer- 
cury, and  liquid  hydrogen  far  lower  still.  These  are  cases  of  boil- 
ing, nevertheless,  though  it  seems  a  paradox  according  to  the  ideas 
we  commonly  attach  to  this  word.  But  such  ideas  are  based  on 
our  common  experience  of  the  properties  of  our  commonest  of 
liquids— viz.  water. 

When  water  boils  under  the  conditions  of  our  ordinary  experience, 
the  passage  from  the  liquid  to  the  gaseous  state  is  a  sudden  leap,  with 
no  intermediate  state  of  existence  that  we  are  able  to  perceive  ;  and 
the  conditions  upon  which  water  is  converted  into  steam— the  liquid 
into  the  gas — while  both  are  at  the  bottom  of  our  atmospheric  ocean, 
are  such  as  to  render  an  intermediate  condition  rationally,  as  well  as 
practically,  impossible. 

We  find  that  the  expansive  energy  by  which  the  steam  is  enabled 
to  resist  atmospheric  pressure  is  conferred  upon  it  by  its  taking  into 
itself,  and  utilizing  for  its  expansive  efforts,  a  large  amount  of  calor- 
ific energy.  When  any  given  quantity  of  water  is  converted  into 
steam,  under  ordinary  circumstances,  its  bulk  suddenly  becomes  above 
1700  times  greater — a  cubic  inch  of  water  forms  about  a  cubic  foot  of 
steam,  and  nearly  1000  degrees  of  heat  (966-6)  disappears  as  tempera- 
ture. Otherwise  stated,  we  must  give  to  the  cubic  inch  of  water  at 
212°  as  much  heat  as  would  raise  it  to  a  temperature  of  212  plus 
966-6  or  1178-6°  if  it  remained  liquid.  This  is  about  the  temperature 
of  the  glowing  coals  of  a  common  fire  ;  but  the  steam  that  has  thus 
taken  enough  heat  to  make  the  water  red  hot  is  still  at  212° — no  hotter 
than  the  water  was  while  boiling. 

This  heat,  which  thus  ceases  to  exhibit  itself  as  temperature,  is 
otherwise  occupied.  Its  energy  is  partly  devoted  to  the  work  of  in- 
creasing the  bulk  of  the  water  to  the  above-named  extent,  and  partly 
in  conferring  on  the  steam  its  gaseous  speciality — that  is,  in  over- 
coming liquid  cohesion,  and  substituting  for  it  the  opposite  property 
of  internal  repulsive  energy  which  is  characteristic  of  gases.  My 
reasons  for  thus  defining  and  separating  these  two  functions  of  the 
so-called  "  latent' '  heat  will  be  seen  when  we  come  to  the  philosophy 
of  the  interesting  researches  of  Dr.  Andrews. 

As  already  explained,  all  gases  are  now  proved  to  be  analogous  to 
steam  ;  they  are  matter  expanded  and  rendered  self-repulsive  by 
heat.  All  elementary  matter  may  exist  in  either  of  the  three  forms — 
solid,  liquid,  or  gas,  according  to  the  amount  of  heat  and  pressure  to 
which  it  is  subjected.  I  limit  this  wide  generalization  to  elementary 
substances  for  the  following  reasons. 

Many  compounds  are  made  up  of  elements  so  feebly  held  together 
that  they  become  "  dissociated  "  when  heated  to  a  temperature  below 
their  boiling-point.  Or  their  condition  may  be  otherwise  defined  by 
stating  that  the  bonds  of  chemical  energy,  which  hold  their  elements 
together,  are  weaker  than  the  cohesion  which  binds  and  holds  them 


302  SCIENCE   IN   SHORT   CHAPTERS. 

in  the  condition  of  solid  or  liquid,  and  are  more  easily  broken  by  the 
expansive  energy  of  heat. 

To  illustrate  this,  let  us  take  two  common  and  well-known  oils, 
olive  oil  and  turpentine.  The  first  belongs  to  the  class  of  "  fixed 
oils,"  the  second  to  the  "  volatile  oils."  If  we  apply  heat  to  liquid 
turpentine,  it  boils,  passes  into  the  state  of  gaseous  turpentine, 
which  is  easily  condensible  by  cooling  it.  If  the  liquid  result  of  this 
condensation  is  examined,  we  find  it  to  be  turpentine  as  before. 
Not  so  with  the  olive  oil.  Just  as  this  reaches  its  boiling-point,  the 
heat,  which  would  otherwise  convert  it  into  olive-oil  vapor,  begins 
to  dissociate  its  constituents,  and  if  the  temperature  be  raised  a  little 
higher,  we  obtain  some  gases,  but  these  are  the  products  of  decompo- 
sition, not  gaseous  olive  oil.  This  is  called  "  destructive' '  distilla- 
tion. 

In  olive  oil,  the  boiling-point  and  dissociation  point  are  near  to 
each  other.  In  the  case  of  glycerine,  these  points  so  nearly  approxi- 
mate that,  although  we  cannot  distil  it  unbroken  under  ordinary 
atmospheric  pressure,  we  may  do  so  if  some  of  this  pressure  is 
removed.  Under  such  diminished  pressure,  the  boiling-point  is 
brought  down  below  the  dissociation  point,  and  condensible  glycer- 
ine gas  comes  over  without  decomposition. 

Sugar  affords  a  very  interesting  example  of  dissociation,  commenc- 
ing far  below  the  boiling  point,  and  going  on  gradually  and  visibly, 
with  increasing  rapidity  as  the  temperature  is  raised.  Put  some 
white  sugar  into  a  spoon,  and  heat  the  spoon  gradually  over  a  smoke- 
less gas-flame  or  spirit-lamp.  At  first  the  sugar  melts,  then  becomes 
yellow  (barley  sugar)  ;  this  color  deepens  to  orange,  then  red,  then 
chestnut-brown,  then  dark  brown,  then  neary  black  (caramel),  then 
quite  black,  and  finally  it  becomes  a  mere  cinder.  Sugar  is  com- 
posed of  carbon  and  water  ;  the  heat  dissociates  this  compound,  sep- 
arates the  water,  which  passes  off  as  vapor,  and  leaves  the  carbon  be- 
hind. The  gradual  deepening  of  the  color  indicates  the  gradual  car- 
bonization, which  is  completed  when  only  the  dry  insoluble  cinder 
remains.  An  appearance  of  boiling  is  seen,  but  this  is  the  boiling  of 
the  dissociated  water,  not  of  the  sugar. 

The  dissociation  temperature  of  water  is  far  above  its  boiling- 
point.  It  is  5072°  Fahr.,  under  conditions  corresponding  to  those 
which  make  its  boiling-point  212°.  If  we  examine  the  variations  of 
the  boiling-point  of  water,  as  the  atmospheric  pressure  on  its  surface 
varies,  some  curious  results  follow.  To  do  this  the  reader  must 
endure  some  figures.  They  are  extremely  simple,  and  perfectly  in- 
telligible, but  demand  just  a  little  attention. 

Following  are  three  columns  of  figures.  The  first  represents 
atmospheres  of  pressure — i.e.,  taking  our  atmospheric  pressure  when 
it  supports  30  inches  of  mercury  in  the  barometer  tube  as  a  unit, 
that  pressure  is  doubled,  trebled,  etc.  up  to  twenty  times  in  the  first 
column.  The  second  column  states  the  temperature  at  which  water 
boils  when  under  the  different  pressures  thus  indicated.  The  third 
column,  which  is  the  subject  for  special  study  just  now,  shows  how 
much  we  must  raise  the  temperature  of  the  water  in  order  to  make 
it  boil  as  we  go  on  adding  atmospheres  of  pressure  :  or,  in  other 
words,  the  increase  of  temperature  due  to  each  increase  of  one 
atmosphere  of  pressure.  The  figures  are  founded  on  the  experiment 
of  Kegnault. 


SOLIDS,    LIQUIDS,    AKD   GASES.  303 


Pressure  in 
Atmospheres. 
1 
2 

Temperature  F. 

o 

.        .        .       212 
249'5 

Rive  of  Temperature 
for  each  addit  oiial 
Atmosphere. 

.      37-5 

3 

$2733 

23  '8 

4 

291  2 

17'9 

5 

306'0 

14'8 

6 

318'2 

12'2 

7 

329'6 

11'4 

g 

339'5 

9-9 

9 

3484 

8'9 

10 

35G"6 

8*2 

11 

3fi4"2 

7'6 

12 

371'1 

6*9 

14 

384-0 

62 

15 

3'XVO 

6'0 

16 

395-4 

5'4 

17 

400'8 

5-4 

18 

405-9 

5'1 

19 

410'8 

4'9 

20 

415-4 

4'6 

It  may  be  seen  from  the  above  that,  with  the  exception  of  one 
irregularity,  there  is  a  continual  diminution  of  the  additional  tem- 
perature which  is  required  to  overcome  an  additional  atmosphere  of 
pressure,  and  if  this  goes  on  as  the  pressure  and  temperatures  ad- 
vance, we  may  ultimately  reach  a  curious  condition— a  temperature 
at  which  additional  pressure  will  demand  no  additional  temperature 
to  maintain  the  gaseous  state  ;  or,  in  other  words,  a  temperature  may 
be  reached  at  which  no  amount  of  pressure  can  condense  steam  into 
water,  or  at  which  the  gaseous  and  liquid  states  merge  or  become 
indifferent. 

But  we  must  not  push  this  mere  numerical  reasoning  too  far,  see- 
ing that  it  is  quite  possible  to  be  continually  approaching  a  given 
point,  without  ever  reaching  it,  as  when  we  go  on  continually  halv- 
ing the  remaining  distance.  The  figures  in  the  above  do  not  appear 
to  follow  according  to  such  a  law — nor,  indeed,  any  other  regularity. 
This  probably  arises  from  experimental  error,  as  there  are  discrepan- 
cies in  the  results  of  different  investigators.  They  all  agree,  how- 
ever, in  the  broad  fact  of  the  gradation  above  stated.  Dulong  and 
Arago,  who  directed  the  experiments  of  the  French  Government 
Commission  for  investigating  this  subject,  state  the  pressure  at  20 
atmospheres  to  be  4184,  at  21  -  422-9,  at  22  =  427-3,  at  13  =  431-4, 
and  at  24  atmospheres,  their  highest  experimental  limit,  435-5,  thus  re- 
ducing the  rise  of  temperature  between  the  23d  and  24th  atmosphere 
to  4-1. 

If  we  could  go  on  heating  water  in  a  transparent  vessel  until  this 
difference  became  a  vanishing  quantity,  we  should  probably  recog- 
nize a  visible  physical  change  coincident  with  this  cessation  of  con- 
densibility  by  pressure  ;  but  this  is  not  possible,  as  glass  would  be- 
come red-hot  and  softened,  and  thus  incapable  of  bearing  the  great 
Pressure  demanded.  Besides  this,  glass  is  soluble  in  water  at  these 
igh  temperatures. 

If,  however,  we  can  find  some  liquid  with  a  lower  boiling-point,  we 
may  go  on  piling  atmosphere  upon  atmosphere  of  elastic  expansive 
pressure,  as  the  temperature  is  raised,  without  reaching  an  unman- 
ageable degree  of  heat.  Liquid  carbonic  acid,  which,  under  a  single 
atmosphere  of  pressure,  boils  at  112°  below  the  zero  of  our  thermom- 


304  SCIENCE  IK  SHORT  CHAPTERS. 

eter,  may  thus  be  raised  to  a  temperature  having  the  same  relation  to 
its  boiling-point  that  a  red-heat  has  to  that  of  water,  and  may  be 
still  confined  within  a  glass  vessel,  provided  the  walls  of  the  vessel 
are  sufficiently  thick  to  bear  the  strain  of  the  elastic  outstriving 
pressure.  '  In  spite  of  its  brittleness,  glass  is  capable  of  bearing  an 
enormous  strain  steadily  applied,  as  may  be  proved  by  trying  to  break 
even  a  mere  thread  of  glass  by  direct  pull. 

Dr.  Andrews  thus  treated  carbonic  a«id,  and  the  experiment,  as  I 
have  witnessed  its  repetition,  is  very  curious.  A  liquid  occupies  the 
lower  part  of  a  very  strong  glass  tube,  which  appears  empty  above. 
But  this  apparent  void  is  occupied  by  invisible  carbonic  acid  gas, 
evolved  by  the  previous  boiling  of  the  liquid  carbonic  acid  below. 
We  start  at  a  low  temperature  -say  40°  Fahr.  Then  the  temperature 
is  raised  ;  the  liquid  boils  until  it  has  given  off  sufficient  gas  or  vapor 
to  exert  the  full  expansive  pressure  or  tension  due  to  that  tempera- 
ture. This  pressure  stops  the  boiling,  and  again  the  surface  of  the 
liquid  is  becalmed. 

This  is  repeated  at  a  higher  temperature,  and  thus  continued  until 
we  approach  nearly  to  88°  Fahr.,  when  the  surface  of  the  liquid  loses 
some  of  its  sharp  outline.  Then  88°  is  reached,  and  the  boundary 
between  liquid  and  gas  vanishes  ;  liquid  and  gas  have  blended  into 
one  mysterious  intermediate  fluid  ;  an  indefinite  fluctuating  some- 
thing is  there  filling  the  whole  of  the  tube — an  etherealized  liquid  or 
a  visible  gas.  Hold  a  red-hot  poker  between  your  eye  and  the  light  ; 
you  will  see  an  upflowing  wavy  movement  of  what  appears  like  liquid 
air.  The  appearance  of  the  hybrid  fluid  in  the  tube  resembles  this, 
but  is  sensibly  denser,  and  evidently  stands  between  the  liquid  and 
gaseous  states  of  matter,  as  pitch  or  treacle  stands  between  solid  and 
liquid. 

The  temperature  at  which  this  occurs  has  been  named  by  Dr.  An- 
drews the  "  <riti<-al  temperature  / '  here  the  gaseous  and  liquid  states 
are  "  continuous,"  and  it  is  probable  that  all  other  substances  capable 
of  existing  in  both  states  have  their  own  particular  critical  tempera- 
tures. 

Having  thus  stated  the  facts  in  popular  outline,  I  shall  conclude 
the  subject  by  indulging  in  some  speculations  of  my  own  on  the  phi- 
losophy of  these  general  facts  or  natural  laws,  and  on  some  of  their 
possible  consequences. 

As  already  stated,  the  conversion  of  water  into  steam  under  ordi- 
nary atmospheric  pressure  demands  966-6°  of  heat  over  and  above 
that  which  does  the  work  of  raising  the  water  to  212°,  or,  otherwise 
stated,  as  much  heat  is  at  work  in  a  given  weight  of  steam  at  212° 
as  would  raise  the  same  quantity  of  water  to  1178-6°  if  it  remained 
liquid. 

James  Watt  concluded  from  his  experiments  that  a  given  weight  of 
steam,  whatever  may  be  its  density,  or,  in  other  words,  under  what- 
ever pressure  it  may  exist,  contains  the  same  quantity  of  heat.  Ac- 
cording to  this,  if  we  reduced  the  pressure  sufficiently  to  bring  down 
the  boiling  point  to  112°,  instead  of  212°,  the  latent  heat  of  the  steam 
thus  formed  would  be  1066-6°  instead  of  966-6°,  or  if,  on  the  other 
hand,  we  placed  it  under  sufficient  pressure  to  raise  the  boiling  point 
to  312°,  the  latent  heat  of  the  steam  would  be  reduced  to  866-6°— i.e., 
only  866-6°  more  would  be  required  to  convert  the  water  into  steam. 
If  the  boiling  point  were  412°,  as  it  is  between  19  and  20  atmospheres 


SOLIDS,    LIQUIDS,    AXD    GASES.  305 

of  pressure,  only  766-6°  more  heat  would  be  required,  and  so  on,  till 
we  reached  a  pressure  which  raised  the  boiling  point  to  1178-6°  ;  the 
water  would  then  become  steam  without  further  heating — i.e.,  the 
critical  point  would  be  reached,  and  thus,  if  Watt  is  right,  we  can 
easily  determine,  theoretically,  the  critical  temperature  of  water.* 

Mr.  Perkins,  who  made  some  remarkable  experiments  upon  very 
high  pressure  steam  many  years  ago,  and  exhibited  a  steam  gun  at 
the  Adelaide  Gallery,  stated  that  red-hot  water  does  not  boil  ;  that  if 
the  generator  be  sufficiently  strong  to  stand  a  pressure  of  60,000  Ibs. 
load  on  the  safety-valve,  the  water  may  be  made  to  exert  a  pressure 
of  56,000  Ibs.  on  the  square  inch  at  a  cherry-red  heat  without  boiling. 
He  made  a  number  of  lather  dangerous  experiments  in  thus  raising 
water  to  a  red  heat,  and  his  assertion  that  red-hot  water  does  not 
boil  is  curious  when  viewed  in  connection  with  Dr.  Andrews'  experi- 
ments. 

I  cannot  tell  how  he  arrived  at  this  conclusion,  having  been  unable 
to  obtain  the  original  record  of  his  experiments,  and  only  quote  the 
above  second-hand.  It  is  worthy  of  remark  that  the  temperature  he 
names  is  about  1170°,  or  that  which,  if  Watt  is  right,  must  be  the 
critical  temperature  of  the  water.  Perkins'  red-hot  water  would  not 
boil,  being  then  in  the  intermediate  condition. 

So  far,  we  have  a  nice  little  theory,  which  not  only  shows  how  the 
critical  state  of  water  must  be  reached,  but  also  its  precise  tempera- 
ture ;  but  all  this  is  based  on  the  assumption  that  Watt  made  no 
mistake. 

Unfortunately  for  the  simplicity  of  this  theory,  Regnault  states 
that  his  experiments  contradict  those  of  Watt,  and  prove  that  the 
latent  heat  of  steam  does  not  diminish  just  in  the  same  degree  as  the 
boiling-point  is  raised,  but  that  instead  of  this  the  diminution  of  the 
latent  heat  progresses  30 £  per  cent,  more  slowly  than  the  rise  of 
temperature,  so  that,  instead  of  the  latent  heat  of  steam  between 
boiling-points  of  212°  and  31'.T  falling  from  966-6°  to  866-6°  it  would 
only  fall  to  895-1°  or  69-5°  of  latent  heat  for  every  100°  of  tempera- 
ture. 

If  this  is  correct,  the  temperature  at  which  the  latent  heat  of  steam 
is  reduced  to  zero  is  much  higher  than  1178 -6%  and  is,  in  fact,  a 
continually  receding  quantity  never  absolutely  reached  ;  but  I  am 
not  prepared  to  accept  these  figures  of  Begnault  as  implicitly  as  is 
now  done  in  text-books  (I  was  nearly  saying  "  as  is  now  the  fashion"), 
seeing  that  they  are  not  the  actual  figures  obtained  by  his  experi- 
ments, but  those  of  his  "  empirical  formulae"  based  upon  them.  His 
actual  experimental  figures  are  very  irregular  ;  thus,  between  steam 
temperature  of  171-6°  and  183-2°  a  difference  of  11-6°,  the  experi- 
mental difference  in  the  latent  heat  came  out  as  4-7°  ;  between  steam 
temperature  of  183-2°  and  194-8°,  or  11-6°  again,  the  latent  heat 
difference  is  tabulated  as  8-0°. 

Regnault' s  experiments  were  not  carried  to  very  high  temperatures 
and  pressures,  and  indicate  that  as  these  advance  the  deviation  from 
Watt's  law  diminishes,  and  may  finally  vanish  at  about  1500°  or 
1600°,  where  the  latent  heat  would  reach  zero,  and  there,  according 
to  the  above,  the  critical  temperature  would  be  reached.  Any  addi- 

*  Watt's  own  figure  for  the  latent  heat  of  steam  at  212°  was  950  =  ,  but  I  adopt 
that  which  is  now" generally  accepted. 


306  SCIENCE   IK   SHORT   CHAPTERS. 

tional  heat  applied  after  this  will  have  but  one  function  to  perform, 
viz.  the  ordinary  work  of  increasing  the  bulk  of  the  heated  body 
without  doing  anything  further  in  the  way  of  conferring  upon  it  any 
new  self-repulsive  properties. 

Our  notions  of  solids,  liquids,  and  gases  are  derived  from  our 
experiences  of  the  state  of  matter  here  upon  this  earth.  Could  we 
be  removed  to  another  planet,  they  would  be  curiously  changed.  On 
Mercury  water  would  rank  as  one  of  the  condensible  gases  ;  on  Mars, 
as  a  fusible  solid  ;  but  what  on  Jupiter  ? 

Recent  observations  justify  us  in  regarding  this  as  a  miniature  sun, 
with  an  external  envelope  of  cloudy  matter,  apparently  of  partially 
condensed  water,  but  red-hot,  or  probably  still  hotter  within.  His 
vaporous  atmosphere  is  evidently  of  enormous  depth,  and  the  force  of 
gravitation  being  on  his  visible  outer  surface  2£  times  greater  than 
that  on  our  earth's  surface,  the  atmospheric  pressure  in  descending 
below  this  visible  surface  must  soon  reach  that  at  which  the  vapor  of 
water  would  be  brought  to  its  critical  condition.  Therefore  we  may 
infer  that  the  oceans  of  Jupiter  are  neither  of  frozen,  liquid,  nor 
gaseous  water,  but  are  oceans  or  atmospheres  of  critical  water.  If  any 
fish-birds  swim  or  fly  therein  they  must  be  very  critically  organized. 

As  the  whole  mass  of  Jupiter  is  300  times  greater  than  that  of  the 
earth,  and  its  compressing  energy  toward  the  centre  proportional  to 
this,  its  materials,  if  similar  to  those  of  the  earth  and  no  hotter, 
would  be  considerably  more  dense,  and  the  whole  planet  would  have 
a  higher  specific  gravity  ;  but  we  know  by  the  movement  of  its  satel- 
lites that,  instead  of  this,  its  specific  gravity  is  less  than  a  fourth  of 
that  of  the  earth.  This  justifies  the  conclusion  that  it  is  intensely 
hot,  for  even  hydrogen,  if  cold,  would  become  denser  than  Jupiter 
under  such  pressure. 

As  all  elementary  substances  may  exist  as  solids,  liquids,  or  gases, 
or  critically,  according  to  the  conditions  of  temperature  and  press- 
ure, I  am  justified  in  hypothetically  concluding  that  Jupiter  is 
neither  a  solid,  a  liquid,  nor  a  gaseous  planet,  but  a  critical  planet,  or 
an  orb  composed  internally  of  dissociated  elements  in  the  critical 
state,  and  surrounded  by  a  dense  atmosphere  of  their  vapors,  and 
those  of  some  of  their  compounds,  such  as  water.  The  same  reason- 
ing applies  to  Saturn  and  the  other  large  and  rarefied  planets. 

The  critical  temperature  of  the  dissociated  elements  of  the  sun  is 
probably  reached  at  the  base  of  the  photosphere,  or  that  region 
revealed  to  us  by  the  sun-spots.  When  I  wrote  "  The  Fuel  of  the 
Sun,"  thirteen  or  fourteen  years  ago,  I  suggested,  on  the  above 
grounds,  the  then  heretical  idea  of  the  red-heat  of  Jupiter,  Saturn, 
Uranus,  and  Neptune,  and  showed  that  all  such  compounds  as  water 
must  be  dissociated  at  the  base  of  the  sun's  atmosphere  ;  but  being 
then  unacquainted  with  the  existence  of  this  critical  state  of  matter, 
I  supposed  the  dissociated  elements  to  exist  as  gases  with  a  small 
solid  nucleus  or  kernel  in  the  centre. 

Applying  now  the  researches  of  Dr.  Andrews  to  the  conditions  of 
solar  existence,  as  I  formerly  applied  the  dissociation  researches  of 
Deville,  I  conclude  that  the  sun  has  no  nucleus,  either  solid,  liquid, 
or  gaseous,  but  is  composed  of  dissociated  matter  in  the  critical  state, 
surrounded,  first,  by  a  flaming  envelope  due  to  the  recombination  of 
the  dissociated  matter,  and  outside  of  this  another  envelope  of 
vapors  due  to  this  combination. 


MURCHISOtf   AXD   BABBAGE.  307 

CHAPTER  XLIV. 

MUECHISON   AND   BABBAGE. 

THE  curious  contrast  of  character  presented  by  these  two  eminent 
men,  and  the  very  different  course  of  their  lives,  conveys  a  striking 
lesson  to  all  those  superficial  thinkers  and  unthinking  talkers  who 
make  sweeping  generalizations  concerning  human  character,  who  as- 
sume as  a  matter  of  course  that  any  man  who  writes  poetry  must  be 
merely  a  dreamer  of  day-dreams,  incapable  of  transacting  any  practi- 
cal daily  business,  and  not  at  all  reliable  in  money  matters  ;  whose 
eyes  are  always  "  in  a  fine  frenzy  rolling  ;"  that  he  is,  in  short,  a  sort 
of  amiable,  harmless  lunatic.  All  actors,  according  to  such  people, 
are  dissipated  spendthrifts  ;  and  if  Sims  Reeves,  or  any  other  public 
performer,  is  prevented  by  delicate  larynx  or  other  indisposition 
from  appearing,  they  look  knowing,  shrug  their  shoulders,  wink 
wisely,  and  assume,  without  the  faintest  shadow  of  evidence,  that  he 
is  drunk. 

In  like  manner  they  set  up  a  typical  philosopher  of  their  own 
manufacture,  and  attribute  his  imaginary  character  to  all  who  devote 
themselves  to  science.  Their  philosopher  is  a  musty,  dried-up, 
absent-minded  pedant,  whose  ordinary  conversation  is  conducted  in 
words  of  seven  syllables,  who  is  always  lost  in  profound  abstractions  ; 
takes  no  interest  in  common  things  ;  regards  music,  dancing,  play- 
acting, poetry,  and  every  cheerful  pursuit  as  frivolous  and  contempti- 
ble— a  creature  who  never  makes  a  joke,  seldom  laughs,  and  who  in 
matters  of  business  is  even  more  incapable  than  the  poet. 

The  singular  contrast  of  character  presented  by  Babbage  and  Mur- 
chison  affords  at  once  a  most  complete  refutation  of  such  generaliza- 
tions. Here  were  two  men,  both  philosophers,  one  the  very  type  of 
amiability,  suavity,  and  all  conceivable  polish,  the  verj'  perfection  of 
a  courtier,  but  differing  from  the  vulgar  courtier  of  the  Court  in  this 
respect,  that  his  high-toned  courtesy  was  not  bestowed  upon  kings 
only,  but  also  upon  all  his  human  brethren,  and  with  especial  grace- 
fulness upon  those  whose  rank  was  below  his  own. 

I  doubt  whether  there  is  any  man  now  living,  or  has  lived  during 
this  generation,  that  could  equal  Sir  Koderick  Murchison  in  the  art 
of  distributing  showers  of  compliments  upon  a  large  number  of 
different  people  in  succession,  and  making  each  recipient  delightfully 
satisfied  with  himself.  In  his  position  as  Chairman  to  the  Geological 
Section  of  the  British  Association,  he  did  this  with  marvellous  tact, 
without  the  least  fulsomeness  or  repetition,  or  any  display  of  patron- 
izing. Every  man  who  read  a  paper  before  that  section  was  better 
than  ever  satisfied  with  the  great  merits  and  vast  importance  of  his 
communication,  after  hearing  the  Chairman's  comments  upon  it. 
None  but  a  most  detestably  strong-minded  and  logical  brute  could 
resist  the  insinuating  flattery  of  Sir  Roderick. 

How  different  was  poor  Babbage  !  Who  that  attends  any  sort  of 
scientific  gatherings  has  not  seen  Sir  Eoderick  ?  but  who  in  the  world 
excepting  the  organ-grinders  and  the  police  magistrate  has  ever  seen 
Babbage,  or  even  his  portrait  ?  What  a  contrast  between  the  seclu- 
sion and  the  public  existence  ;  between  the  hedgehog  bristles  and  the 
velvet  softness,  of  the  one  and  the  other  ! 


308  SCIENCE    IX    SHORT    CHAPTERS. 

Those  who  were  on  intimate  terms  with  Babbage  (I  have  never  met 
or  heard  of  such  a  person)  could  probably  tell  us  that  all  his  irrita- 
bility and  roughness  was  outside,  and  that,  in  the  absence  of  organ- 
grinders,  he  was  a  kind  and  amiable  gentleman  ;  but,  even  admitting 
this,  the  contrast  between  the  two  philosophers  is  as  great  as  could 
well  be  found  between  any  two  men  following  the  most  widely 
divergent  studies  or  professions. 

Those  who  would  reply  that  mathematics  and  geology  are  such 
different  studies  have  only  to  go  a  little  further  back  on  the  death- 
roll,  and  they  will  find  the  name  of  De  Morgan,  a  pure  mathematician 
like  Babbage.  He  was  a  man  of  exuberant  fun  and  humor,  and  so 
far  from  hating  music  of  either  a  humble  or  pretentious  character, 
was  a  highly  accomplished  musician,  both  theoretical  and  practical, 
and  if  we  are  to  believe  confidential  pornrnunications,  one  of  hia 
favorite  instruments  was  the  penny  whistle,  on  which  he  was  a  most 
original  and  peculiar  performer. 

I  had  not  intended  to  reprint  the  above,  which  was  written  just 
after  the  death  of  Murchison  and  Babbage,  but  the  comments  that 
have  recently  followed  the  death  of  Darwin  induce  me  to  do  so. 

Many  have  expressed  their  surprise  at  the  unanimous  expressions 
of  Darwin's  friends  concerning  the  geniality  of  his  disposition,  his 
gentleness,  cheerfulness  ;  his  genuine  humility  and  simplicity  of 
character. 

A  third  type  of  character  is  here  presented,  and  that  which  corre- 
sponds most  correctly  with  the  true  ideal  of  a  modern  philosopher, 
also  represented  by  that  great  master  of  experimental  science,  Fara- 
day. In  both  of  these  there  was  the  full  measure  of  Murchison's 
amiability,  but  without  the  courtly  polish  of  the  ex-soldier.  Phil- 
osophic meditation  and  close  application  to  original  research  may, 
and  often  does,  induce  a  certain  degree  of  shyness  due  to  a  conscious- 
ness of  the  social  disqualification  which  arises  from  that  inability  to 
fulfil  all  the  demands  for  small  attentions  which  constitute  conven- 
tional politeness  ;  a  disability  due  to  habits  of  consecutive  thought 
and  mental  abstraction. 

A  sensitive  and  amiable  man  would  suffer  much  pain  on  finding 
that  he  had  neglected  to  supply  the  small  wants  of  the  lady  sitting 
next  to  him  at  a  dinner  party,  and  would  withdraw  himself  from  the 
risk  of  repeating  such  unwitting  rudeness.  This  holding  back  from 
ordinary  society,  though  really  due  to  a  conscientious  sense  of  social 
duty  and  tender  regard  for  the  feelings  of  others  is  too  often  referred 
to  a  churlish  unsociality  or  arrogant  assumption  of  superiority. 

If  Newton  really  did  mistake  the  lady's  finger  for  a  tobacco-stopper, 
depend  upon  it  the  pain  he  suffered  was  far  more  acute  than  that 
which  he  inflicted,  and  was  suffered  over  and  over  again  whenever 
the  incident  was  recollected. 


THE    END. 


309 

OLOTH-BOTJlsriD 

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Analytical  Biblical  Treasury. 

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310          PUBLICATIONS  OF  FUNK  &  WAGXALLS,  .\jffW  YORK. 

These  Sayings  of  Mine. 

"  These  Sayings  of  Mine."  Sermons  on  Seven  Chapters  of  the  First 
Gospel.  By  JOSEPH  PAEKER,  D.D.  With  -an  introduction  by  Dr, 
Deems.  8vo,  cloth,  320  pp.,  $1.50. 

Through  the  Prison  to  the  Throne. 

Through  tbe  Prison  to  ths  Throne.  Illustrations  of  Life  from  the 
Biography  of  Joseph.  By  Rev.  JOSEPH  S.  VAN  DYKE,  author  of 
"Popery  the  Foe  of  the  Church  and  of  the  Republic."  IGmo, 
cloth,  254  pp.,  $1.00. 

The  Treasury  of  David. 

By  Rev  .  CHAELES  H.  SPUEGEON.    8vo,  cloth.    Price  per  volume,  $2.00. 

Spurgeon's  Authorization.  —  "Messrs.  I.  K.  Funk  &  Co.  have  entered 
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the  United  States.  I  have  every  confidence  in  them  that  they  will 
issue  it  correctly  and  worthily.  It  has  been  the  great  literary  work 
of  my  life,  and  I  trust  it  will  be  as  kindly  received  in  America  as 
in  England.  I  wish  for  Messrs.  Funk  success  in  a  venture  whick 
must  involve  a  great  risk  and  much  outlay. 

"Dec.  8,  1881.  C.  H.  SPUEGEON." 

Complete  in  7  volumes.     First  G  volumes  now  complete. 

Philip  ftchaff,  D.D  ,  tht  Eminent  Commentator  and  the  President  of  the  American 
Bible  Revision  Committee,  says:  "The  most  important  and  practical  work  of  the 
age  on  the  Psalter  is  '  The  Treasury  of  David,'  by  Charles  H  Spurgeon.  It  is  full 
oc  the  force  and  genius  of  this  celebrated  preacher,  and  rich  in  selections  from 
the  entire  range  of  literature." 

William  M.  Taylor,  D.D.,  New  York,  says:  "In  the  exposition  of  the  heart 
'  The  Treasury  of  David  '  is  sui  generis  rich  in  experience  and  pre-eminently  devo- 
tional. The  exposition  is  always  fresh.  To  the  preacher  it  is  especially  sug- 
gestive." 

John  Hall,  D.D.,  New  York,  says:  "  There  are  two  questions  that  must  inter- 
ee*  every  expositor  of  the  Divine  Word.  What  does  a  particular  passage  mean, 
and  to  what  use  is  it  to  be  applied  in  public  teaching  ?  In  the  department  of  the 
latter  Mr.  Spurgeon's  great  work  on  the  Psalms  is  without  an  equal.  Eminently 
practical  in  his  own  teaching,  he  has  collected  in  these  volumes  the  best  thoughts 
of  the  best  minds  on  the  Psalter,  and  especially  of  that  great  bociy  loosely  grouped 
together  as  the  Puritan  divines.  I  am  heartily  glad  that  by  arrangements  satis- 
factory to  all  concerned  the  Messrs.  Funk  &  Co.  are  about  to  bring  this  great  work 
within  the  reach  of  ministers  everywhere,  as  the  English  edition  is  nccessar.ly 
expensive.  I  wish  the  highest  success  to  the  enterprise." 


Van  Doren's  Commentary. 

A  Suggestive  Commentary  on  Luke,  with  Critical  and  Homiletical 
Notes.  By  W.  H.  VAN  DOEEN,  D.D.  Edited  by  Prof.  James 
Kernahan,  London.  4  vols.,  paper,  1104  pp.  (Standard  Series, 
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311 

THE  STANDARD  LIBRARY, 

WHAT    REPRESENTATIVE    CLERGYMEN    SAY 

OF  IT. 

Chas.  II.    Hall,    D.D.,   Holy  Trinity  Episcopal  Church,  Brooklyn, 

says  : 

"  Great  book  monopolies,  like  huge  railroad  syndicates,  are  now  the  mo- 
narchical relics  against  which  the  benevolence  and  radicalism  of  the  age, 
from  different  standpoints,  are  bound  to  wage  war.  Each  source  will  have 
its  own  motives  and  arguments,  but  each  will  resolve  to  conquer  in  the  long- 
run.  At  one  end  of  the  scale  we  have  the  Life  of  Dickens  offered  for  $800, 
that  some  one  wealthy  man  may  enjoy  the  comfort  of  his  proud  privilege 
of  wealth  in  having  what  no  other  mortal  possesses  ;  at  the  other,  we  find 
the  volume  offered  at  10  or  20  cents,  which  any  newsboy  or  thoughtful 
laborer  uses  in  common  with  thousands.  In  the  great  strife  for  the  great- 
Grit  good  of  the  largest  number,  put  me  down  as  on  the  side  of  the  last.  I 
enclose  my  subscription  order  for  a  year." 

Rev.   Chas.  W.  Cashing,    D.D.,    First  M.   E.  Church,  Rochester, 

N.  Y.,  says  : 

"  One  of  the  most  pernicious  sources  of  evil  among  our  young  people 
is  the  books  they  read.  When  I  can  get  a  young  man  interested  in  substan- 
tial books,  I  have  great  hope  of  him.  For  this  reason  I  have  been  deeply 
interested  in  your  effort  to  make  good  books  as  cheap  as  bad  ones.  I  men- 
tioned the  matter  from  my  pulpit.  As  a  result  I  at  once  got  fifty-four  sub- 
scribers for  the  full  set,  and  more  to  come." 

J.  O.  Peck,  D.D.,  First  M.  E.  Church,  Brooklyn,  N.  Y.,  says: 

"  Your  effort  is  commendable.  You  ought  to  have  the  co-operation  of 
all  good  men.  It  is  a  moral,  heroic,  and  humane  enterprise." 

Pres.  Mark  Hopkins,  D.D.,  of  Williams  College,  says : 

"The  attempt  of  Messrs.  Funk  and  Wagnalls  to  place  good  literature 
within  reach  of  the  masses  is  worthy  of  all  commendation  and  encourage- 
ment. If  the  plan  can  be  successfully  carried  out,  it  will  be  a  great  boon 
to  the  country." 

Geo.  C.  liOrrimer,   D.D.,  Baptist  Church,  Chicago,  says  : 

"I  sincerely  hope  your  endeavors  to  circulate  a  wholesome  and  elevat- 
ing class  of  books  win  prove  successful.  Certainly,  clergymen,  and  Chris- 
tians generally,  cannot  afford  that  it  should  fail.  *In  proof  of  my  personal 
interest  in  your  endeavors,  I  subscribe  for  a.year." 

J.  P.  Newman,   D.D.,  New  York,  says  : 

"  I  have  had  faith  from  the  beginning  in  the  mission  of  Messrs.  Funk  & 
Wagnalls.  It  required  great  faith  on  their  part,  and  their  success  is  in 
proof  that  all  things  are  possible  to  him  that  believeth.  They  have  done 
for  the  public  what  long  was  needed,  but  what  other  publishers  did  not 
venture  to  do." 

Henry  J.  Van  Dyke,  D.D.,  Presbyterian  Church,  Brooklyn,  N.  Y., 

says : 

11  Good  books  are  great  blessings.  They  drive  out  darkness  by  letting 
in  light.  Your  plan  ought  not  to  fail  for  lack  of  support.  Put  my  name 
on  the  list  of  subscribers." 


312 

T.  W.  Chambers,  D.D.,  Collegiate  Reformed  Church,  New  York,  says : 
"  The  plan  seems  to  me  both  praiseworthy  and  feasible.    I  trust  it  will 
meet  with  speedy  and  abundant  success." 

Sylvester  F.  Scovel,  D.D.,    First  Presbyterian  Church,    Pittsburgh 
Pa.,  says  : 

"Your  plans  deserve  a  place  in  the  category  of  moral  reforms.  The 
foes'they  meet,  the  width  of  the  battle-ground  they  can  be  expanded  to 
cover,  the  manifold  incidental  blessings  they  may  convey  to  thousands  of 
households,  the  national  and  international  currents  of  thought  they  may 
set  in  motion,  entitle  them  beyond  all  question  to  prompt  and  efficient  aid 
from  clergymen  and  the  whole  Christian  Church." 

Ezra  Abbot,  D.D.,  LL.D.,  of  Harvard  College,  says  : 

"  I  heartily  approve  of  your  project.  I  shall  be  glad  to  receive  and 
commend  the  volumes  to  buyers.  I  send  you  my  subscription." 

Thos.  Armitage,   D.D.,  Fifth  Avenue  Baptist    Church,  New  York, 

says : 

"  Your  plan  is  grand  and  philanthropic.  I  wish  you  success,  and  ask 
you  to  put  me  down  for  one  set,  with  the  assurance  that  I  will  aid  you  by 
every  kind  word  which  opportunity  suggests." 

William  M.  Taylor,  D.D.,  Broadway  Tabernacle,  New  York,  says  : 

"  The  success  of  the  plan  depends  very  much  on  the  character  of  the 
books  selected  ;  but  if  you  are  wise  in  that  particular,  as  I  have  no  doubt, 
you  will  be  benefactors  to  many  struggling  readers  in  whose  experience  a 
new  book  is  one  of  the  rarest  treats.  I  am  glad  to  see,  too,  that  you  are 
making  arrangements  with  the  English  publishers,  so  that  in  conferring 
a  boon  upon  readers  here  you  will  not  be  doing  injustice  to  authors  across 
the  sea." 

James  Eells,  D.D.,  Lane  Theological  Seminary,  Cincinnati,  O.,  says  : 
"  From  the  reputation  of  your  house  I  am  ready  to  believe  that  you  will 
publish  only  worthy  books.    I  heartily  wish  you  success." 

E.  J.  Wolf,  D.D.,  of  the  Lutheran  Seminary,  Gettysburg,  Pa.,  says  : 

"  A  more  laudable  project  1  can  hardly  conceive  of.  Vicious  literature 
has  long  had  the  advantage  in  that  it  was  put  within  easy  reach  of  the 
masses.  The  poverty  of  many  who  fain  would  use  the  very  best  books  has 
often  distressed  me.  I  feel  in  my  heart  that  the  noble  enterprise  of  your 
house  is  deserving  of  the  most  liberal  encouragement." 

Bishop  Samuel  Fallows,    Reformed  Episcopalian  Church,   Chicago, 

says : 

"Your  plan  for  supplying  the  masses  with  the  best  reading  at  such  a 
nominal  price  cannot  be  too  highly  commended." 

J.  JL.  Burrows,  D.D.,  Baptist  Church,  Norfolk,  Va.,  says  : 

"  Every  endeavor  to  supersede  poison  by  food  for  the  people  deserves 
encouragement." 

Rev.  W.  F.  Crafts,  Lee  Avenue  Congregationalist  Church,  Brooklyn, 

says  : 

"In  the  West  they  displace  the  worthless  prairie  grass  by  sowing  blue 
grass.  The  soil  is  too' rich  to  be  inactive.  It  will  have  a  right  or  wrong 
activity.  So  about  the  love  of  reading  in  the  young.  It  is  prime  soil  and 
will  bear  tall  wire  grass  if  we  do  not  give  it  blue  grass.  It  will  have  bad 
reading,  if  the  good,  equally  cheap  and  attractive,  is  not  provided." 


Books    for    a    Trifle. 

THESE  books  are  printed  in  readable  type,  on  fair  paper,  and  are  bound  in  postal 
card  manilla. 

These  books  are  printed  wholly  without  abridgment,  except  Canon  Farrar'a  "  Life 
of  Christ "  and  his  "  Life  of  Paul." 


Wo.  Pri«u 

1.  John  Ploughman's  Talk.    C.  H. 
Spnrgeon.    On  Choice  of  Books. 
Thomas  Carlyle.    4to.    Both. . . .  JO  12 

2.  Manliness   of    Christ.     Thomas 
Hughes.    4to 10 

3.  Essays.    Lord  Macaulay.    4to. . .        15 

4.  Light  of  Asia.  Edwin  Arnold.  4to.        15 

5.  Imitation  of  Christ.    Thomas  a 
Kempis.    4to 15 

6-7.  Life  of  Christ.    Canon  Farrar. 

4to 50 

8.  Essays.    Thomas  Carlyle.    4to..        20 
9-10.  Life  and  Work  of  St.  Paul. 

Canon  Farrar.   4to   2  parts,  both       50 
11.  Self-Culture.    Prof.J.S.  Blackie. 

4to.    2parts,both 10 

12-19.  Popular  History  of  England. 

Chas.  Knight.    4to 280 

20-21.  Ruskin's  Letters  to  Workmen 

and  Laborers.   4to.   2  parts,  both       30 

22.  Idyls  of  the  King.    Alfred  Tenny- 
son.   4to 20 

23.  Life  of  Rowland  Hill.    Rev.  V.  J. 
Charlesworth.    4to 15 

24.  Town  Geology.    Charles  Kings- 
ley.    4to 15 

25.  Alfred  the  Great.    Thos.  Hughes. 

4to 20 

26.  Outdoor  Life  in  Europe.    Rev.  E. 

P.  Thwing.    4to 20 

27.  Calamities  of  Authors.    I.  D'ls- 
raeli.    4to 20 

28.  Salon  of  Madame  Necker.    Parti. 

4to 15 

29.  Ethics  of  the  Dust.   John  Buskin. 

4to 15 

30-31.  Memories  of  My  Exile.  Louis 

Kossuth.  4to 40 

32.  Mister  Horn  and  His  Friends. 

Illustrated.  4to 15 

33-34.  Orations  of  Demosthenes.  4to.  40 

35.  Frondes  Agrestes.     John  Ru«- 

kin.    4to IS 

36.  Joan  of  Arc.    Alphonse  de  La- 
martine.    4to 10 

37.  Thoughts  of  M.  AureKus  Anto- 
ninus.   4to 15 

38.  Salon  of  Madame  Necker.    Part 

II.    4to 15 

39.  The  Hermits.  Chas.  Kingeley.  4to.       15 

40.  John  Ploughman"^  Pictures.    C. 

H .  Spnrgeon.    4to 15 

41.  Pulpit  Table-Talk.    Dean  Ram- 
say.   4to 10 

42.  Bible    and    Newspaper.      C.    H. 
Spurgeon.    4to 15 

43.  Lacon.    Rev.  C.  C.  Colton.    4to.  20 


No.  Prie*. 

44.  Goldsmith's  Citizen  of  the  World. 

4to $0  20 

45.  America  Revisited.    George  Au- 
gustus Sala.    4to 20 

46.  Life  of  C.  H.  Spurgeon.    8vo 5J9 

47.  John  Calvin.    M.  Guizot.    4to...        15 
48-49.  Dickens'    Christmas    Books, 

Illustrated.    8vo 50 

50.  Shairp's  Culture  and  Religion.  8vo.     15 
51-52.  Grodet's  Commentary  on  Lake. 
Ed. by  Dr.  John  Hall.  8vo,2parts, 

both 206 

53.  Diary  of  a  Minister's  Wife.    Part 

L    8vo 15 

54-57.  Van  Doren's  Suggestive  Com- 
mentary on  Luke.    New  edition,     • 
enlarged.    8vo 3  00 

58.  Diary  of  a  Minister's  Wife.    Part 

II.  8vo 15 

59.  The  Nutritive  Cure.    Dr.  Robert 

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